From 65ff401cde277d2d2e6c91ac553c7b1946e0f011 Mon Sep 17 00:00:00 2001
From: dipeshmsft <dipeshkumar@microsoft.com>
Date: Mon, 28 Apr 2025 22:11:31 +0530
Subject: [PATCH 1/6] Fixed ComboBox style and template

---
 .../Resources/Theme/Dark.xaml                 |  34 +-
 .../Resources/Theme/HC.xaml                   |  36 +-
 .../Resources/Theme/Light.xaml                |  43 +-
 .../Resources/Variables.xaml                  |   1 -
 .../Styles/ComboBox.xaml                      | 696 +++++++++++-------
 .../Themes/Fluent.Dark.xaml                   | 441 +++++++----
 .../Themes/Fluent.HC.xaml                     | 441 +++++++----
 .../Themes/Fluent.Light.xaml                  | 449 +++++++----
 8 files changed, 1429 insertions(+), 712 deletions(-)

diff --git a/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Resources/Theme/Dark.xaml b/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Resources/Theme/Dark.xaml
index 33f3e897914..7aad07b90fe 100644
--- a/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Resources/Theme/Dark.xaml
+++ b/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Resources/Theme/Dark.xaml
@@ -468,17 +468,45 @@
 
     <!--  ComboBox  -->
     <SolidColorBrush x:Key="ComboBoxBackground" Color="{StaticResource ControlFillColorDefault}" />
-    <SolidColorBrush x:Key="ComboBoxBackgroundFocused" Color="{StaticResource ControlFillColorDefault}" />
     <SolidColorBrush x:Key="ComboBoxBackgroundPointerOver" Color="{StaticResource ControlFillColorSecondary}" />
+    <SolidColorBrush x:Key="ComboBoxBackgroundPressed" Color="{StaticResource ControlFillColorTertiary}" />
     <SolidColorBrush x:Key="ComboBoxBackgroundDisabled" Color="{StaticResource ControlFillColorDisabled}" />
     <SolidColorBrush x:Key="ComboBoxForeground" Color="{StaticResource TextFillColorPrimary}" />
+    <SolidColorBrush x:Key="ComboBoxForegroundPointerOver" Color="{StaticResource TextFillColorPrimary}" />
+    <SolidColorBrush x:Key="ComboBoxForegroundPressed" Color="{StaticResource TextFillColorPrimary}" />
     <SolidColorBrush x:Key="ComboBoxForegroundDisabled" Color="{StaticResource TextFillColorDisabled}" />
-    <!--<SolidColorBrush x:Key="ComboBoxItemBorderBrush" Color="{StaticResource ControlElevationBorderBrush}" />-->
+    <SolidColorBrush x:Key="ComboBoxForegroundFocused" Color="{StaticResource TextFillColorPrimary}" />
+    <SolidColorBrush x:Key="ComboBoxForegroundFocusedPressed" Color="{StaticResource TextFillColorPrimary}" />
+    <LinearGradientBrush x:Key="ComboBoxBorderBrush" MappingMode="Absolute" StartPoint="0,0" EndPoint="0,3">
+        <LinearGradientBrush.GradientStops>
+            <GradientStop Offset="0.33" Color="{StaticResource ControlStrokeColorSecondary}" />
+            <GradientStop Offset="1.0" Color="{StaticResource ControlStrokeColorDefault}" />
+        </LinearGradientBrush.GradientStops>
+    </LinearGradientBrush>
+    <LinearGradientBrush x:Key="ComboBoxBorderBrushPointerOver" MappingMode="Absolute" StartPoint="0,0" EndPoint="0,3">
+        <LinearGradientBrush.GradientStops>
+            <GradientStop Offset="0.33" Color="{StaticResource ControlStrokeColorSecondary}" />
+            <GradientStop Offset="1.0" Color="{StaticResource ControlStrokeColorDefault}" />
+        </LinearGradientBrush.GradientStops>
+    </LinearGradientBrush>
+    <SolidColorBrush x:Key="ComboBoxBorderBrushPressed" Color="{StaticResource ControlStrokeColorDefault}" />
     <SolidColorBrush x:Key="ComboBoxBorderBrushDisabled" Color="{StaticResource ControlStrokeColorDefault}" />
-    <SolidColorBrush x:Key="ComboBoxBorderBrushFocused" Color="{StaticResource SystemAccentColorLight2}" />
     <SolidColorBrush x:Key="ComboBoxDropDownGlyphForeground" Color="{StaticResource TextFillColorSecondary}" />
+    <SolidColorBrush x:Key="ComboBoxDropDownGlyphForegroundFocused" Color="{StaticResource TextFillColorSecondary}" />
+    <SolidColorBrush x:Key="ComboBoxDropDownGlyphForegroundFocusedPressed" Color="{StaticResource TextFillColorSecondary}" />
+    <SolidColorBrush x:Key="ComboBoxDropDownGlyphForegroundDisabled" Color="{StaticResource TextFillColorDisabled}" />
+    <SolidColorBrush x:Key="ComboBoxDropDownForeground" Color="{StaticResource TextFillColorPrimary}" />
     <SolidColorBrush x:Key="ComboBoxDropDownBackground" Color="{StaticResource AcrylicBackgroundFillColorDefault}" />
     <SolidColorBrush x:Key="ComboBoxDropDownBorderBrush" Color="{StaticResource SurfaceStrokeColorFlyout}" />
+    <SolidColorBrush x:Key="ComboBoxDropDownBackgroundPointerOver" Color="{StaticResource SubtleFillColorSecondary}" />
+    <SolidColorBrush x:Key="ComboBoxDropDownBackgroundPointerPressed" Color="{StaticResource SubtleFillColorTertiary}" />
+    <SolidColorBrush x:Key="ComboBoxFocusedDropDownBackgroundPointerPressed" Color="{StaticResource ControlAltFillColorQuarternary}" />
+    <SolidColorBrush x:Key="ComboBoxEditableDropDownGlyphForeground" Color="{StaticResource TextFillColorSecondary}" />
+
+    <!-- Deprecated ComboBox brushes -->
+        <SolidColorBrush x:Key="ComboBoxBorderBrushFocused" Color="{StaticResource SystemAccentColorLight2}" />
+
+    <!--<SolidColorBrush x:Key="ComboBoxItemBorderBrush" Color="{StaticResource ControlElevationBorderBrush}" />-->
     <SolidColorBrush x:Key="ComboBoxItemPillFillBrush" Color="{StaticResource SystemAccentColorLight2}" />
     <SolidColorBrush x:Key="ComboBoxItemBackgroundSelected" Color="{StaticResource SubtleFillColorSecondary}" />
     <SolidColorBrush x:Key="ComboBoxItemForeground" Color="{StaticResource TextFillColorPrimary}" />
diff --git a/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Resources/Theme/HC.xaml b/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Resources/Theme/HC.xaml
index 75e7ce4cc26..2379990a0a4 100644
--- a/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Resources/Theme/HC.xaml
+++ b/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Resources/Theme/HC.xaml
@@ -297,22 +297,40 @@
 
     <!--  ComboBox  -->
     <SolidColorBrush x:Key="ComboBoxBackground" Color="{StaticResource SystemColorButtonFaceColor}" />
-    <SolidColorBrush x:Key="ComboBoxBackgroundFocused" Color="{StaticResource SystemColorHighlightTextColor}" />
-    <SolidColorBrush x:Key="ComboBoxBackgroundPointerOver" Color="{StaticResource SystemColorHighlightTextColor}" />
-    <SolidColorBrush x:Key="ComboBoxBackgroundDisabled" Color="{StaticResource SystemColorWindowColor}" />
+    <SolidColorBrush x:Key="ComboBoxBackgroundPointerOver" Color="{StaticResource SystemColorWindowColor}" />
+    <SolidColorBrush x:Key="ComboBoxBackgroundPressed" Color="{StaticResource SystemColorButtonFaceColor}" />
+    <SolidColorBrush x:Key="ComboBoxBackgroundDisabled" Color="{StaticResource SystemColorButtonFaceColor}" />
     <SolidColorBrush x:Key="ComboBoxForeground" Color="{StaticResource SystemColorButtonTextColor}" />
+    <SolidColorBrush x:Key="ComboBoxForegroundPointerOver" Color="{StaticResource SystemColorButtonTextColor}" />
+    <SolidColorBrush x:Key="ComboBoxForegroundPressed" Color="{StaticResource SystemColorButtonTextColor}" />
     <SolidColorBrush x:Key="ComboBoxForegroundDisabled" Color="{StaticResource SystemColorGrayTextColor}" />
+    <SolidColorBrush x:Key="ComboBoxForegroundFocused" Color="{StaticResource SystemColorButtonTextColor}" />
+    <SolidColorBrush x:Key="ComboBoxForegroundFocusedPressed" Color="{StaticResource SystemColorButtonTextColor}" />
+    <SolidColorBrush x:Key="ComboBoxBorderBrush" Color="{StaticResource SystemColorButtonTextColor}" />
+    <SolidColorBrush x:Key="ComboBoxBorderBrushPointerOver" Color="{StaticResource SystemColorHighlightColor}" />
+    <SolidColorBrush x:Key="ComboBoxBorderBrushPressed" Color="{StaticResource SystemColorHighlightColor}" />
+    <SolidColorBrush x:Key="ComboBoxBorderBrushDisabled" Color="{StaticResource SystemColorGrayTextColor}" />
+    <SolidColorBrush x:Key="ComboBoxDropDownGlyphForeground" Color="{StaticResource SystemColorButtonTextColor}" />
+    <SolidColorBrush x:Key="ComboBoxDropDownGlyphForegroundFocused" Color="{StaticResource SystemColorButtonTextColor}" />
+    <SolidColorBrush x:Key="ComboBoxDropDownGlyphForegroundFocusedPressed" Color="{StaticResource SystemColorButtonTextColor}" />
+    <SolidColorBrush x:Key="ComboBoxDropDownGlyphForegroundDisabled" Color="{StaticResource SystemColorGrayTextColor}" />
+    <SolidColorBrush x:Key="ComboBoxDropDownForeground" Color="{StaticResource SystemColorButtonTextColor}" />
+    <SolidColorBrush x:Key="ComboBoxDropDownBackground" Color="{StaticResource SystemColorButtonFaceColor}" />
+    <SolidColorBrush x:Key="ComboBoxDropDownBorderBrush" Color="{StaticResource SystemColorButtonTextColor}" />
+    <SolidColorBrush x:Key="ComboBoxDropDownBackgroundPointerOver" Color="{StaticResource SystemColorWindowColor}" />
+    <SolidColorBrush x:Key="ComboBoxDropDownBackgroundPointerPressed" Color="{StaticResource SystemColorButtonFaceColor}" />
+    <SolidColorBrush x:Key="ComboBoxFocusedDropDownBackgroundPointerPressed" Color="{StaticResource SystemColorButtonFaceColor}" />
+    <SolidColorBrush x:Key="ComboBoxEditableDropDownGlyphForeground" Color="{StaticResource SystemColorButtonTextColor}" />
+
+    <!-- Deprecated ComboBox brushes -->
+        <SolidColorBrush x:Key="ComboBoxBorderBrushFocused" Color="{StaticResource SystemColorHighlightTextColor}" />
+    
     <!--<SolidColorBrush x:Key="ComboBoxItemBorderBrush" Color="{StaticResource ControlElevationBorderBrush}" />-->
-    <SolidColorBrush x:Key="ComboBoxBorderBrushDisabled" Color="{StaticResource SystemColorWindowColor}" />
-    <SolidColorBrush x:Key="ComboBoxBorderBrushFocused" Color="{StaticResource SystemColorHighlightTextColor}" />
-    <SolidColorBrush x:Key="ComboBoxDropDownGlyphForeground" Color="{StaticResource SystemColorGrayTextColor}" />
-    <SolidColorBrush x:Key="ComboBoxDropDownBackground" Color="{StaticResource SystemColorWindowColor}" />
-    <SolidColorBrush x:Key="ComboBoxDropDownBorderBrush" Color="{StaticResource SystemColorWindowTextColor}" />
     <SolidColorBrush x:Key="ComboBoxItemPillFillBrush" Color="{StaticResource SystemColorHighlightColor}" />
     <SolidColorBrush x:Key="ComboBoxItemBackgroundSelected" Color="{StaticResource SystemColorWindowColor}" />
     <SolidColorBrush x:Key="ComboBoxItemForeground" Color="{StaticResource SystemColorButtonTextColor}" />
     <SolidColorBrush x:Key="ComboBoxItemForegroundSelected" Color="{StaticResource SystemColorHighlightColor}" />
-
+    
     <!--  ContentDialog  -->
     <SolidColorBrush
         x:Key="ContentDialogSmokeFill"
diff --git a/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Resources/Theme/Light.xaml b/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Resources/Theme/Light.xaml
index 01b77c9fff4..f220b8980e8 100644
--- a/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Resources/Theme/Light.xaml
+++ b/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Resources/Theme/Light.xaml
@@ -477,22 +477,57 @@
 
     <!--  ComboBox  -->
     <SolidColorBrush x:Key="ComboBoxBackground" Color="{StaticResource ControlFillColorDefault}" />
-    <SolidColorBrush x:Key="ComboBoxBackgroundFocused" Color="{StaticResource ControlFillColorDefault}" />
     <SolidColorBrush x:Key="ComboBoxBackgroundPointerOver" Color="{StaticResource ControlFillColorSecondary}" />
+    <SolidColorBrush x:Key="ComboBoxBackgroundPressed" Color="{StaticResource ControlFillColorTertiary}" />
     <SolidColorBrush x:Key="ComboBoxBackgroundDisabled" Color="{StaticResource ControlFillColorDisabled}" />
     <SolidColorBrush x:Key="ComboBoxForeground" Color="{StaticResource TextFillColorPrimary}" />
+    <SolidColorBrush x:Key="ComboBoxForegroundPointerOver" Color="{StaticResource TextFillColorPrimary}" />
+    <SolidColorBrush x:Key="ComboBoxForegroundPressed" Color="{StaticResource TextFillColorPrimary}" />
     <SolidColorBrush x:Key="ComboBoxForegroundDisabled" Color="{StaticResource TextFillColorDisabled}" />
-    <!--<SolidColorBrush x:Key="ComboBoxItemBorderBrush" Color="{StaticResource ControlElevationBorderBrush}" />-->
+    <SolidColorBrush x:Key="ComboBoxForegroundFocused" Color="{StaticResource TextFillColorPrimary}" />
+    <SolidColorBrush x:Key="ComboBoxForegroundFocusedPressed" Color="{StaticResource TextFillColorPrimary}" />
+    <LinearGradientBrush x:Key="ComboBoxBorderBrush" MappingMode="Absolute" StartPoint="0,0" EndPoint="0,3">
+        <LinearGradientBrush.RelativeTransform>
+            <ScaleTransform ScaleY="-1" CenterY="0.5" />
+        </LinearGradientBrush.RelativeTransform>
+        <LinearGradientBrush.GradientStops>
+            <GradientStop Offset="0.33" Color="{StaticResource ControlStrokeColorSecondary}" />
+            <GradientStop Offset="1.0" Color="{StaticResource ControlStrokeColorDefault}" />
+        </LinearGradientBrush.GradientStops>
+    </LinearGradientBrush>
+    <LinearGradientBrush x:Key="ComboBoxBorderBrushPointerOver" MappingMode="Absolute" StartPoint="0,0" EndPoint="0,3">
+        <LinearGradientBrush.RelativeTransform>
+            <ScaleTransform ScaleY="-1" CenterY="0.5" />
+        </LinearGradientBrush.RelativeTransform>
+        <LinearGradientBrush.GradientStops>
+            <GradientStop Offset="0.33" Color="{StaticResource ControlStrokeColorSecondary}" />
+            <GradientStop Offset="1.0" Color="{StaticResource ControlStrokeColorDefault}" />
+        </LinearGradientBrush.GradientStops>
+    </LinearGradientBrush>
+    <SolidColorBrush x:Key="ComboBoxBorderBrushPressed" Color="{StaticResource ControlStrokeColorDefault}" />
     <SolidColorBrush x:Key="ComboBoxBorderBrushDisabled" Color="{StaticResource ControlStrokeColorDefault}" />
-    <SolidColorBrush x:Key="ComboBoxBorderBrushFocused" Color="{StaticResource SystemAccentColorDark1}" />
-    <SolidColorBrush x:Key="ComboBoxDropDownGlyphForeground" Color="{StaticResource TextFillColorPrimary}" />
+    <SolidColorBrush x:Key="ComboBoxDropDownGlyphForeground" Color="{StaticResource TextFillColorSecondary}" />
+    <SolidColorBrush x:Key="ComboBoxDropDownGlyphForegroundFocused" Color="{StaticResource TextFillColorSecondary}" />
+    <SolidColorBrush x:Key="ComboBoxDropDownGlyphForegroundFocusedPressed" Color="{StaticResource TextFillColorSecondary}" />
+    <SolidColorBrush x:Key="ComboBoxDropDownGlyphForegroundDisabled" Color="{StaticResource TextFillColorDisabled}" />
+    <SolidColorBrush x:Key="ComboBoxDropDownForeground" Color="{StaticResource TextFillColorPrimary}" />
     <SolidColorBrush x:Key="ComboBoxDropDownBackground" Color="{StaticResource AcrylicBackgroundFillColorDefault}" />
     <SolidColorBrush x:Key="ComboBoxDropDownBorderBrush" Color="{StaticResource SurfaceStrokeColorFlyout}" />
+    <SolidColorBrush x:Key="ComboBoxDropDownBackgroundPointerOver" Color="{StaticResource SubtleFillColorSecondary}" />
+    <SolidColorBrush x:Key="ComboBoxDropDownBackgroundPointerPressed" Color="{StaticResource SubtleFillColorTertiary}" />
+    <SolidColorBrush x:Key="ComboBoxFocusedDropDownBackgroundPointerPressed" Color="{StaticResource ControlAltFillColorQuarternary}" />
+    <SolidColorBrush x:Key="ComboBoxEditableDropDownGlyphForeground" Color="{StaticResource TextFillColorSecondary}" />
+
+    <!-- Deprecated ComboBox Brushes -->
+        <SolidColorBrush x:Key="ComboBoxBorderBrushFocused" Color="{StaticResource SystemAccentColorDark1}" />
+
+    <!--<SolidColorBrush x:Key="ComboBoxItemBorderBrush" Color="{StaticResource ControlElevationBorderBrush}" />-->
     <SolidColorBrush x:Key="ComboBoxItemPillFillBrush" Color="{StaticResource SystemAccentColorDark1}" />
     <SolidColorBrush x:Key="ComboBoxItemBackgroundSelected" Color="{StaticResource SubtleFillColorSecondary}" />
     <SolidColorBrush x:Key="ComboBoxItemForeground" Color="{StaticResource TextFillColorPrimary}" />
     <SolidColorBrush x:Key="ComboBoxItemForegroundSelected" Color="{StaticResource TextFillColorPrimary}" />
 
+    
     <!--  ContentDialog  -->
     <SolidColorBrush x:Key="ContentDialogSmokeFill" Color="{StaticResource SmokeFillColorDefault}" />
     <SolidColorBrush x:Key="ContentDialogBackground" Color="{StaticResource SolidBackgroundFillColorBase}" />
diff --git a/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Resources/Variables.xaml b/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Resources/Variables.xaml
index 5d2c6aeba17..c9172d5c427 100644
--- a/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Resources/Variables.xaml
+++ b/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Resources/Variables.xaml
@@ -43,7 +43,6 @@
     <Thickness x:Key="TimePickerHostPadding">0,1,0,2</Thickness>
     <Thickness x:Key="DatePickerHostPadding">0,1,0,2</Thickness>
     <Thickness x:Key="DatePickerHostMonthPadding">9,0,0,1</Thickness>
-    <Thickness x:Key="ComboBoxEditableTextPadding">10,0,30,0</Thickness>
     <Thickness x:Key="TextControlErrorBorderPadding">1</Thickness>
 
     <system:Double x:Key="ComboBoxMinHeight">24</system:Double>
diff --git a/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Styles/ComboBox.xaml b/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Styles/ComboBox.xaml
index d3e7a07ff3b..7c324846e8c 100644
--- a/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Styles/ComboBox.xaml
+++ b/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Styles/ComboBox.xaml
@@ -14,56 +14,99 @@
     xmlns:controls="clr-namespace:System.Windows.Controls;assembly=PresentationFramework"
     xmlns:system="clr-namespace:System;assembly=System.Runtime">
 
-    <Thickness x:Key="ComboBoxPadding">10,8,10,8</Thickness>
+    <!-- Deprecated .NET 9 Keys -->
+        <Thickness x:Key="ComboBoxAccentBorderThemeThickness">0,0,0,2</Thickness>
+        <Thickness x:Key="ComboBoxChevronMargin">8,0,10,0</Thickness>
+        <!-- Redefined in .NET 10 -->
+            <!-- <Thickness x:Key="ComboBoxPadding">10,8,10,8</Thickness>
+            <system:Double x:Key="ComboBoxChevronSize">11</system:Double> -->
+
+    <Thickness x:Key="ComboBoxPadding">12,5,0,7</Thickness>
+    <Thickness x:Key="ComboBoxEditableTextPadding">11,5,38,6</Thickness>
     <Thickness x:Key="ComboBoxBorderThemeThickness">1,1,1,1</Thickness>
-    <Thickness x:Key="ComboBoxAccentBorderThemeThickness">0,0,0,2</Thickness>
-    <Thickness x:Key="ComboBoxChevronMargin">8,0,10,0</Thickness>
-    <Thickness x:Key="ComboBoxItemMargin">3,2,3,0</Thickness>
-    <Thickness x:Key="ComboBoxItemContentMargin">10,8,8,8</Thickness>
-    <system:Double x:Key="ComboBoxChevronSize">11.0</system:Double>
+    <system:Double x:Key="ComboBoxChevronSize">10</system:Double>
     <system:Double x:Key="ComboBoxPopupMinHeight">32.0</system:Double>
     <system:String x:Key="ComboBoxChevronDownGlyph">&#xE70D;</system:String>    
+    <CornerRadius x:Key="ComboBoxDropDownButtonBackgroundCornerRadius">4</CornerRadius>
+
+    <Thickness x:Key="ComboBoxItemMargin">3,2,3,0</Thickness>
+    <Thickness x:Key="ComboBoxItemContentMargin">10,8,8,8</Thickness>
 
     <Style x:Key="DefaultComboBoxTextBoxStyle" TargetType="{x:Type TextBox}">
-        <!--  Focus by parent element  -->
         <Setter Property="FocusVisualStyle" Value="{x:Null}" />
-        <!--  Focus by parent element  -->
-        <!--  Universal WPF UI ContextMenu  -->
         <Setter Property="ContextMenu" Value="{DynamicResource DefaultControlContextMenu}" />
-        <!--  Universal WPF UI ContextMenu  -->
-        <Setter Property="Foreground" Value="{DynamicResource ComboBoxForeground}" />
-        <Setter Property="CaretBrush" Value="{DynamicResource ComboBoxForeground}" />
-        <Setter Property="Background" Value="Transparent" />
-        <Setter Property="Visibility" Value="Hidden" />
+        <Setter Property="Foreground" Value="{DynamicResource TextControlForeground}" />
+        <Setter Property="CaretBrush" Value="{DynamicResource TextControlForeground}" />
+        <Setter Property="BorderBrush" Value="{DynamicResource TextControlElevationBorderBrush}" />
+        <Setter Property="BorderThickness" Value="{StaticResource TextControlBorderThemeThickness}" />
+        <Setter Property="ScrollViewer.HorizontalScrollBarVisibility" Value="Hidden" />
+        <Setter Property="ScrollViewer.VerticalScrollBarVisibility" Value="Hidden" />
+        <Setter Property="HorizontalContentAlignment" Value="Left" />
+        <Setter Property="VerticalContentAlignment" Value="Top" />
         <Setter Property="Cursor" Value="IBeam" />
-        <Setter Property="Margin" Value="0" />
-        <Setter Property="Padding" Value="0" />
-        <Setter Property="SnapsToDevicePixels" Value="True" />
+        <Setter Property="MinHeight" Value="{DynamicResource TextBoxThemeMinHeight}" />
+        <Setter Property="MinWidth" Value="{DynamicResource TextControlThemeMinWidth}" />
+        <Setter Property="Padding" Value="{DynamicResource TextControlThemePadding}" />
+        <Setter Property="Border.CornerRadius" Value="{DynamicResource ControlCornerRadius}" />
+        <Setter Property="AllowDrop" Value="True"/>
+        <Setter Property="ScrollViewer.PanningMode" Value="VerticalFirst"/>
+        <Setter Property="Stylus.IsFlicksEnabled" Value="False"/>
         <Setter Property="OverridesDefaultStyle" Value="True" />
+        <Setter Property="SelectionBrush" Value="{DynamicResource TextControlSelectionHighlightColor}"/>
         <Setter Property="Template">
             <Setter.Value>
-                <ControlTemplate TargetType="{x:Type TextBox}">
-                    <Decorator
-                        x:Name="PART_ContentHost"
-                        Margin="{TemplateBinding Padding}"
-                        HorizontalAlignment="Stretch"
-                        VerticalAlignment="Stretch"
-                        TextElement.Foreground="{TemplateBinding Foreground}" />
+                <ControlTemplate TargetType="{x:Type TextBoxBase}">
+                    <Grid>
+                        <Border
+                            x:Name="ContentBorder"
+                            MinWidth="{TemplateBinding MinWidth}"
+                            MinHeight="{TemplateBinding MinHeight}"
+                            Background="{TemplateBinding Background}"
+                            BorderBrush="{TemplateBinding BorderBrush}"
+                            BorderThickness="{TemplateBinding BorderThickness}"
+                            CornerRadius="{TemplateBinding Border.CornerRadius}" />
+
+                        <ScrollViewer
+                            x:Name="PART_ContentHost"
+                            Margin="{TemplateBinding BorderThickness}"
+                            CanContentScroll="{TemplateBinding ScrollViewer.CanContentScroll}"
+                            HorizontalScrollBarVisibility="{TemplateBinding ScrollViewer.HorizontalScrollBarVisibility}"
+                            IsDeferredScrollingEnabled="{TemplateBinding ScrollViewer.IsDeferredScrollingEnabled}"
+                            IsTabStop="{TemplateBinding ScrollViewer.IsTabStop}"
+                            Padding="{TemplateBinding Padding}"
+                            TextElement.Foreground="{TemplateBinding Foreground}"
+                            VerticalScrollBarVisibility="{TemplateBinding ScrollViewer.VerticalScrollBarVisibility}" />
+                    </Grid>
+                    <ControlTemplate.Triggers>
+                        <Trigger Property="IsMouseOver" Value="True">
+                            <!-- Disabling this trigger as this will be handled by the ComboBox style. -->
+                            <!--<Setter TargetName="ContentBorder" Property="Background" Value="{DynamicResource TextControlBackgroundPointerOver}" />-->
+                            <Setter TargetName="ContentBorder" Property="BorderBrush" Value="{DynamicResource TextControlBorderBrushPointerOver}" />
+                            <Setter TargetName="PART_ContentHost" Property="Foreground" Value="{DynamicResource TextControlForegroundPointerOver}" />
+                        </Trigger>
+                        <Trigger Property="IsFocused" Value="True">
+                            <Setter TargetName="ContentBorder" Property="BorderThickness" Value="{StaticResource TextControlBorderThemeThicknessFocused}" />
+                            <Setter TargetName="ContentBorder" Property="Background" Value="{DynamicResource TextControlBackgroundFocused}" />
+                            <Setter TargetName="ContentBorder" Property="BorderBrush" Value="{DynamicResource TextControlBorderBrushFocused}" />
+                            <Setter TargetName="PART_ContentHost" Property="Foreground" Value="{DynamicResource TextControlForegroundFocused}" />
+                        </Trigger>
+                        <Trigger Property="IsEnabled" Value="False">
+                            <Setter TargetName="ContentBorder" Property="Background" Value="{DynamicResource TextControlBackgroundDisabled}" />
+                            <Setter TargetName="ContentBorder" Property="BorderBrush" Value="{DynamicResource TextControlBorderBrushDisabled}" />
+                            <Setter TargetName="PART_ContentHost" Property="Foreground" Value="{DynamicResource TextControlForegroundDisabled}" />
+                        </Trigger>
+                    </ControlTemplate.Triggers>
                 </ControlTemplate>
             </Setter.Value>
         </Setter>
     </Style>
 
     <Style x:Key="DefaultComboBoxToggleButtonStyle" TargetType="{x:Type ToggleButton}">
-        <!--  Focus by parent element  -->
         <Setter Property="FocusVisualStyle" Value="{x:Null}" />
-        <!--  Focus by parent element  -->
         <Setter Property="Foreground" Value="{DynamicResource ComboBoxForeground}" />
         <Setter Property="Background" Value="Transparent" />
         <Setter Property="BorderBrush" Value="Transparent" />
-        <Setter Property="BorderThickness" Value="0" />
-        <Setter Property="Border.CornerRadius" Value="0" />
-        <Setter Property="SnapsToDevicePixels" Value="True" />
+        <Setter Property="Border.CornerRadius" Value="{DynamicResource ControlCornerRadius}" />
         <Setter Property="OverridesDefaultStyle" Value="True" />
         <Setter Property="Template">
             <Setter.Value>
@@ -143,14 +186,381 @@
         </Setter>
     </Style>
 
+    <ControlTemplate x:Key="DefaultComboBoxTemplate" TargetType="{x:Type ComboBox}">
+        <Grid x:Name="LayoutGrid">
+            <Grid.ColumnDefinitions>
+                <ColumnDefinition Width="*" />
+                <ColumnDefinition Width="38" />
+            </Grid.ColumnDefinitions>
+
+            <Border x:Name="ContentBorder"
+                    Grid.ColumnSpan="2"
+                    Background="{TemplateBinding Background}"
+                    BorderBrush="{TemplateBinding BorderBrush}"
+                    BorderThickness="{TemplateBinding BorderThickness}"
+                    CornerRadius="{TemplateBinding Border.CornerRadius}" />
+
+            <ContentPresenter Name="PART_ContentPresenter"
+                              Content="{TemplateBinding SelectionBoxItem}"
+                              ContentTemplate="{TemplateBinding SelectionBoxItemTemplate}"
+                              ContentTemplateSelector="{TemplateBinding ItemTemplateSelector}"
+                              ContentStringFormat="{TemplateBinding SelectionBoxItemStringFormat}"
+                              Margin="{TemplateBinding Padding}"
+                              TextElement.Foreground="{TemplateBinding Foreground}"
+                              HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"
+                              VerticalAlignment="{TemplateBinding VerticalContentAlignment}"
+                              SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"
+                              IsHitTestVisible="False" />
+
+            <ToggleButton x:Name="ToggleButton"
+                          Grid.ColumnSpan="2"
+                          Focusable="False"
+                          IsChecked="{Binding Path=IsDropDownOpen, Mode=TwoWay, RelativeSource={RelativeSource TemplatedParent}}"
+                          Style="{StaticResource DefaultComboBoxToggleButtonStyle}" />
+
+            <TextBlock x:Name="ChevronIcon"
+                       Grid.Column="1"
+                       HorizontalAlignment="Center"
+                       VerticalAlignment="Center"
+                       IsHitTestVisible="False"
+                       RenderTransformOrigin="0.5,0.5"
+                       FontFamily="{DynamicResource SymbolThemeFontFamily}"
+                       FontSize="{StaticResource ComboBoxChevronSize}"
+                       Text="{StaticResource ComboBoxChevronDownGlyph}">
+                <TextBlock.RenderTransform>
+                    <RotateTransform Angle="0" />
+                </TextBlock.RenderTransform>
+            </TextBlock>
+            
+            <Popup x:Name="PART_Popup"
+                   MinWidth="{TemplateBinding ActualWidth}"
+                   AllowsTransparency="True"
+                   Focusable="False"
+                   IsOpen="{TemplateBinding IsDropDownOpen}"
+                   Placement="{TemplateBinding Popup.Placement}"
+                   PopupAnimation="{TemplateBinding Popup.PopupAnimation}"
+                   VerticalOffset="1">
+                <Border x:Name="DropDownBorder"
+                        Padding="0,4,0,6"
+                        Background="{DynamicResource ComboBoxDropDownBackground}"
+                        BorderBrush="{DynamicResource ComboBoxDropDownBorderBrush}"
+                        BorderThickness="1.5"
+                        CornerRadius="{DynamicResource PopupCornerRadius}"
+                        SnapsToDevicePixels="True">
+                    <Border.RenderTransform>
+                        <TranslateTransform />
+                    </Border.RenderTransform>
+                    <Grid>
+                        <ScrollViewer MaxHeight="{TemplateBinding MaxDropDownHeight}"
+                                      SnapsToDevicePixels="True"
+                                      HorizontalScrollBarVisibility="{TemplateBinding ScrollViewer.HorizontalScrollBarVisibility}"
+                                      VerticalScrollBarVisibility="{TemplateBinding ScrollViewer.VerticalScrollBarVisibility}"
+                                      TextElement.FontSize="{TemplateBinding FontSize}"
+                                      TextElement.FontWeight="{TemplateBinding FontWeight}"
+                                      TextElement.Foreground="{TemplateBinding Foreground}">
+                            <StackPanel IsItemsHost="True"
+                                        KeyboardNavigation.DirectionalNavigation="Contained" />
+                        </ScrollViewer>
+                    </Grid>
+                    <Border.Effect>
+                        <DropShadowEffect BlurRadius="20"
+                                          Direction="270"
+                                          Opacity="0.25"
+                                          ShadowDepth="6" />
+                    </Border.Effect>
+                </Border>
+            </Popup>
+        </Grid>
+        <ControlTemplate.Triggers>
+            <Trigger Property="IsDropDownOpen" Value="True">
+                <Trigger.EnterActions>
+                    <BeginStoryboard>
+                        <Storyboard>
+                            <DoubleAnimation
+                                Storyboard.TargetName="ChevronIcon"
+                                Storyboard.TargetProperty="(TextBlock.RenderTransform).(RotateTransform.Angle)"
+                                From="0"
+                                To="180"
+                                Duration="00:00:00.167" />
+                            <DoubleAnimation
+                                Storyboard.TargetName="DropDownBorder"
+                                Storyboard.TargetProperty="(Border.RenderTransform).(TranslateTransform.Y)"
+                                From="-90"
+                                To="0"
+                                Duration="00:00:00.167">
+                                <DoubleAnimation.EasingFunction>
+                                    <CircleEase EasingMode="EaseOut" />
+                                </DoubleAnimation.EasingFunction>
+                            </DoubleAnimation>
+                        </Storyboard>
+                    </BeginStoryboard>
+                </Trigger.EnterActions>
+                <Trigger.ExitActions>
+                    <BeginStoryboard>
+                        <Storyboard>
+                            <DoubleAnimation
+                                Storyboard.TargetName="ChevronIcon"
+                                Storyboard.TargetProperty="(TextBlock.RenderTransform).(RotateTransform.Angle)"
+                                From="180"
+                                To="0"
+                                Duration="00:00:00.167" />
+                        </Storyboard>
+                    </BeginStoryboard>
+                </Trigger.ExitActions>
+            </Trigger>
+
+            <Trigger Property="HasItems" Value="False">
+                <Setter TargetName="DropDownBorder" Property="MinHeight" Value="{StaticResource ComboBoxPopupMinHeight}" />
+            </Trigger>
+
+            <Trigger SourceName="PART_Popup" Property="Popup.AllowsTransparency" Value="False">
+                <Setter TargetName="DropDownBorder" Property="CornerRadius" Value="0" />
+            </Trigger>
+
+            <Trigger Property="IsGrouping" Value="True">
+                <Setter Property="ScrollViewer.CanContentScroll" Value="False" />
+            </Trigger>
+
+            <!--PointerOver state-->
+            <Trigger Property="IsMouseOver" Value="True">
+                <Setter TargetName="ContentBorder" Property="Background" Value="{DynamicResource ComboBoxBackgroundPointerOver}" />
+                <Setter TargetName="ContentBorder" Property="BorderBrush" Value="{DynamicResource ComboBoxBorderBrushPointerOver}" />
+                <Setter TargetName="PART_ContentPresenter" Property="TextElement.Foreground" Value="{DynamicResource ComboBoxForegroundPointerOver}" />
+            </Trigger>
+
+            <!--Pressed state-->
+            <Trigger SourceName="ToggleButton" Property="IsPressed" Value="True">
+                <Setter TargetName="ContentBorder" Property="Background" Value="{DynamicResource ComboBoxBackgroundPressed}" />
+                <Setter TargetName="ContentBorder" Property="BorderBrush" Value="{DynamicResource ComboBoxBorderBrushPressed}" />
+                <Setter TargetName="PART_ContentPresenter" Property="TextElement.Foreground" Value="{DynamicResource ComboBoxForegroundPressed}" />                
+            </Trigger>
+
+            <!--Focused state-->
+            <Trigger Property="IsFocused" Value="True">
+                <Setter TargetName="PART_ContentPresenter" Property="TextElement.Foreground" Value="{DynamicResource ComboBoxForegroundFocused}" />
+                <Setter TargetName="ChevronIcon" Property="Foreground" Value="{DynamicResource ComboBoxDropDownGlyphForegroundFocused}" />
+            </Trigger>
+
+            <!--FocusedPressed state-->
+            <MultiTrigger>
+                <MultiTrigger.Conditions>
+                    <Condition Property="IsFocused" Value="True" />
+                    <Condition SourceName="ToggleButton" Property="IsPressed" Value="True" />
+                </MultiTrigger.Conditions>
+                <Setter TargetName="PART_ContentPresenter" Property="TextElement.Foreground" Value="{DynamicResource ComboBoxForegroundFocusedPressed}" />
+                <Setter TargetName="ChevronIcon" Property="Foreground" Value="{DynamicResource ComboBoxDropDownGlyphForegroundFocusedPressed}" />
+            </MultiTrigger>
+
+            <!--Disabled state-->
+            <Trigger Property="IsEnabled" Value="False">
+                <Setter TargetName="ContentBorder" Property="Background" Value="{DynamicResource ComboBoxBackgroundDisabled}" />
+                <Setter TargetName="ContentBorder" Property="BorderBrush" Value="{DynamicResource ComboBoxBorderBrushDisabled}" />
+                <Setter TargetName="PART_ContentPresenter" Property="TextElement.Foreground" Value="{DynamicResource ComboBoxForegroundDisabled}" />
+                <Setter TargetName="ChevronIcon" Property="Foreground" Value="{DynamicResource ComboBoxDropDownGlyphForegroundDisabled}" />
+            </Trigger>
+        </ControlTemplate.Triggers>
+    </ControlTemplate>
+
+    <ControlTemplate x:Key="EditableComboBoxTemplate" TargetType="{x:Type ComboBox}">
+        <Grid x:Name="LayoutGrid">
+            <Grid.ColumnDefinitions>
+                <ColumnDefinition Width="*" />
+                <ColumnDefinition Width="38" />
+            </Grid.ColumnDefinitions>
+
+            <Border x:Name="ContentBorder"
+                    Grid.ColumnSpan="2"
+                    Background="{TemplateBinding Background}"
+                    BorderBrush="{TemplateBinding BorderBrush}"
+                    BorderThickness="{TemplateBinding BorderThickness}"
+                    CornerRadius="{TemplateBinding Border.CornerRadius}" />
+
+            <TextBox x:Name="PART_EditableTextBox"
+                     Grid.ColumnSpan="2"
+                     Padding="11,5,38,6"
+                     Foreground="{TemplateBinding Foreground}"
+                     FontSize="{TemplateBinding FontSize}"
+                     IsReadOnly="{TemplateBinding IsReadOnly}"
+                     Style="{StaticResource DefaultComboBoxTextBoxStyle}"
+                     AutomationProperties.Name="{TemplateBinding AutomationProperties.Name}" />
+
+            <Border x:Name="DropDownOverlay"
+                    Grid.Column="1"
+                    Margin="4"
+                    Width="30"
+                    Background="Transparent"
+                    CornerRadius="{StaticResource ComboBoxDropDownButtonBackgroundCornerRadius}" />
+            
+            <ToggleButton x:Name="ToggleButton"
+                          Grid.Column="1"
+                          Margin="4"
+                          Focusable="False"
+                          IsChecked="{Binding Path=IsDropDownOpen, Mode=TwoWay, RelativeSource={RelativeSource TemplatedParent}}"
+                          Style="{StaticResource DefaultComboBoxToggleButtonStyle}" />
+
+            <TextBlock x:Name="ChevronIcon"
+                       Grid.Column="1"
+                       HorizontalAlignment="Center"
+                       VerticalAlignment="Center"
+                       IsHitTestVisible="False"
+                       RenderTransformOrigin="0.5,0.5"
+                       FontFamily="{DynamicResource SymbolThemeFontFamily}"
+                       FontSize="{StaticResource ComboBoxChevronSize}"
+                       Text="{StaticResource ComboBoxChevronDownGlyph}">
+                <TextBlock.RenderTransform>
+                    <RotateTransform Angle="0" />
+                </TextBlock.RenderTransform>
+            </TextBlock>
+
+            <Popup x:Name="PART_Popup"
+                   Focusable="False"
+                   AllowsTransparency="True"
+                   MinWidth="{TemplateBinding ActualWidth}"
+                   IsOpen="{TemplateBinding IsDropDownOpen}"
+                   Placement="{TemplateBinding Popup.Placement}"
+                   PopupAnimation="{TemplateBinding Popup.PopupAnimation}"
+                   VerticalOffset="1">
+                <Border x:Name="DropDownBorder"
+                        Padding="0,4,0,6"
+                        BorderThickness="1.5"
+                        Background="{DynamicResource ComboBoxDropDownBackground}"
+                        BorderBrush="{DynamicResource ComboBoxDropDownBorderBrush}"
+                        CornerRadius="{DynamicResource PopupCornerRadius}"
+                        SnapsToDevicePixels="True">
+                    <Border.RenderTransform>
+                        <TranslateTransform />
+                    </Border.RenderTransform>
+                    <Grid>
+                        <ScrollViewer MaxHeight="{TemplateBinding MaxDropDownHeight}"
+                                      SnapsToDevicePixels="True"
+                                      HorizontalScrollBarVisibility="{TemplateBinding ScrollViewer.HorizontalScrollBarVisibility}"
+                                      VerticalScrollBarVisibility="{TemplateBinding ScrollViewer.VerticalScrollBarVisibility}"
+                                      TextElement.FontSize="{TemplateBinding FontSize}"
+                                      TextElement.FontWeight="{TemplateBinding FontWeight}"
+                                      TextElement.Foreground="{TemplateBinding Foreground}">
+                            <StackPanel IsItemsHost="True"
+                                        KeyboardNavigation.DirectionalNavigation="Contained" />
+                        </ScrollViewer>
+                    </Grid>
+                    <Border.Effect>
+                        <DropShadowEffect BlurRadius="20"
+                                          Direction="270"
+                                          Opacity="0.25"
+                                          ShadowDepth="6" />
+                    </Border.Effect>
+                </Border>
+            </Popup>
+        </Grid>
+        <ControlTemplate.Triggers>
+            <Trigger Property="IsDropDownOpen" Value="True">
+                <Trigger.EnterActions>
+                    <BeginStoryboard>
+                        <Storyboard>
+                            <DoubleAnimation
+                                Storyboard.TargetName="ChevronIcon"
+                                Storyboard.TargetProperty="(TextBlock.RenderTransform).(RotateTransform.Angle)"
+                                From="0"
+                                To="180"
+                                Duration="00:00:00.167" />
+                            <DoubleAnimation
+                                Storyboard.TargetName="DropDownBorder"
+                                Storyboard.TargetProperty="(Border.RenderTransform).(TranslateTransform.Y)"
+                                From="-90"
+                                To="0"
+                                Duration="00:00:00.167">
+                                <DoubleAnimation.EasingFunction>
+                                    <CircleEase EasingMode="EaseOut" />
+                                </DoubleAnimation.EasingFunction>
+                            </DoubleAnimation>
+                        </Storyboard>
+                    </BeginStoryboard>
+                </Trigger.EnterActions>
+                <Trigger.ExitActions>
+                    <BeginStoryboard>
+                        <Storyboard>
+                            <DoubleAnimation
+                                Storyboard.TargetName="ChevronIcon"
+                                Storyboard.TargetProperty="(TextBlock.RenderTransform).(RotateTransform.Angle)"
+                                From="180"
+                                To="0"
+                                Duration="00:00:00.167" />
+                        </Storyboard>
+                    </BeginStoryboard>
+                </Trigger.ExitActions>
+            </Trigger>
+
+            <Trigger Property="HasItems" Value="False">
+                <Setter TargetName="DropDownBorder" Property="MinHeight" Value="{StaticResource ComboBoxPopupMinHeight}" />
+            </Trigger>
+
+            <Trigger SourceName="PART_Popup" Property="Popup.AllowsTransparency" Value="False">
+                <Setter TargetName="DropDownBorder" Property="CornerRadius" Value="0" />
+            </Trigger>
+
+            <Trigger Property="IsGrouping" Value="True">
+                <Setter Property="ScrollViewer.CanContentScroll" Value="False" />
+            </Trigger>
+
+            <!-- PointerOver state-->
+            <Trigger Property="IsMouseOver" Value="True">
+                <Setter TargetName="ContentBorder" Property="Background" Value="{DynamicResource ComboBoxBackgroundPointerOver}" />
+                <Setter TargetName="ContentBorder" Property="BorderBrush" Value="{DynamicResource ComboBoxBorderBrushPointerOver}" />
+                <Setter TargetName="PART_EditableTextBox" Property="TextElement.Foreground" Value="{DynamicResource ComboBoxForegroundPointerOver}" />
+            </Trigger>
+
+            <!-- Focused / TextBoxFocused -->
+            <Trigger Property="IsFocused" Value="True">
+                <Setter TargetName="PART_EditableTextBox" Property="TextElement.Foreground" Value="{DynamicResource ComboBoxForegroundFocused}" />
+                <Setter TargetName="ChevronIcon" Property="Foreground" Value="{DynamicResource ComboBoxEditableDropDownGlyphForeground}" />
+            </Trigger>
+
+            <!--TextBoxOverlayPointerOver state-->
+            <Trigger SourceName="ToggleButton" Property="IsMouseOver" Value="True">
+                <Setter TargetName="DropDownOverlay" Property="Background" Value="{DynamicResource ComboBoxDropDownBackgroundPointerOver}" />
+            </Trigger>
+
+            <!--TextBoxOverlayPressed-->
+            <Trigger SourceName="ToggleButton" Property="IsPressed" Value="True">
+                <Setter TargetName="DropDownOverlay" Property="Background" Value="{DynamicResource ComboBoxDropDownBackgroundPointerPressed}" />
+            </Trigger>
+
+            <!--TextBoxFocusedOverlayPointerOver state-->
+            <MultiTrigger>
+                <MultiTrigger.Conditions>
+                    <Condition Property="IsFocused" Value="True" />
+                    <Condition SourceName="ToggleButton" Property="IsMouseOver" Value="True" />
+                </MultiTrigger.Conditions>
+                <Setter TargetName="DropDownOverlay" Property="Background" Value="{DynamicResource ComboBoxDropDownBackgroundPointerOver}" />
+                <Setter TargetName="ChevronIcon" Property="Foreground" Value="{DynamicResource ComboBoxEditableDropDownGlyphForeground}" />
+            </MultiTrigger>
+
+            <!-- FocusedPressed state / TextBoxFocusedOverlayPressed state -->
+            <MultiTrigger>
+                <MultiTrigger.Conditions>
+                    <Condition Property="IsFocused" Value="True" />
+                    <Condition SourceName="ToggleButton" Property="IsPressed" Value="True" />
+                </MultiTrigger.Conditions>
+                <Setter TargetName="ChevronIcon" Property="Foreground" Value="{DynamicResource ComboBoxEditableDropDownGlyphForeground}" />
+                <Setter TargetName="PART_EditableTextBox" Property="TextElement.Foreground" Value="{DynamicResource ComboBoxForegroundFocusedPressed}" />
+                <Setter TargetName="DropDownOverlay" Property="Background" Value="{DynamicResource ComboBoxFocusedDropDownBackgroundPointerPressed}" />
+            </MultiTrigger>
+
+            <!--Disabled state-->
+            <Trigger Property="IsEnabled" Value="False">
+                <Setter TargetName="ContentBorder" Property="Background" Value="{DynamicResource ComboBoxBackgroundDisabled}" />
+                <Setter TargetName="ContentBorder" Property="BorderBrush" Value="{DynamicResource ComboBoxBorderBrushDisabled}" />
+                <Setter TargetName="PART_EditableTextBox" Property="TextElement.Foreground" Value="{DynamicResource ComboBoxForegroundDisabled}" />
+                <Setter TargetName="ChevronIcon" Property="Foreground" Value="{DynamicResource ComboBoxDropDownGlyphForegroundDisabled}" />
+            </Trigger>
+        </ControlTemplate.Triggers>
+    </ControlTemplate>
+ 
     <Style x:Key="DefaultComboBoxStyle" TargetType="{x:Type ComboBox}">
-        <!--  Universal WPF UI focus  -->
         <Setter Property="FocusVisualStyle" Value="{DynamicResource DefaultControlFocusVisualStyle}" />
-        <!--  Universal WPF UI ContextMenu  -->
         <Setter Property="ContextMenu" Value="{DynamicResource DefaultControlContextMenu}" />
         <Setter Property="Foreground" Value="{DynamicResource ComboBoxForeground}" />
         <Setter Property="Background" Value="{DynamicResource ComboBoxBackground}" />
-        <Setter Property="BorderBrush" Value="{DynamicResource ControlElevationBorderBrush}" />
+        <Setter Property="BorderBrush" Value="{DynamicResource ComboBoxBorderBrush}" />
         <Setter Property="BorderThickness" Value="{StaticResource ComboBoxBorderThemeThickness}" />
         <Setter Property="ScrollViewer.CanContentScroll" Value="False" />
         <Setter Property="ScrollViewer.HorizontalScrollBarVisibility" Value="Auto" />
@@ -165,225 +575,15 @@
         <Setter Property="Padding" Value="{DynamicResource ComboBoxPadding}" />
         <Setter Property="Border.CornerRadius" Value="{DynamicResource ControlCornerRadius}" />
         <Setter Property="Popup.PopupAnimation" Value="None" />
-        <!--  WPF doesn't like centering, the animation is ugly and the mouse button sometimes clicks right away.  -->
         <Setter Property="Popup.Placement" Value="Bottom" />
         <Setter Property="SnapsToDevicePixels" Value="True" />
         <Setter Property="OverridesDefaultStyle" Value="True" />
-        <Setter Property="Template">
-            <Setter.Value>
-                <ControlTemplate TargetType="{x:Type ComboBox}">
-                    <Grid>
-                        <Border
-                            x:Name="ContentBorder"
-                            Grid.Row="0"
-                            MinWidth="{TemplateBinding MinWidth}"
-                            MinHeight="{TemplateBinding MinHeight}"
-                            Padding="0"
-                            HorizontalAlignment="Stretch"
-                            VerticalAlignment="Stretch"
-                            Background="{TemplateBinding Background}"
-                            BorderBrush="{TemplateBinding BorderBrush}"
-                            BorderThickness="{TemplateBinding BorderThickness}"
-                            CornerRadius="{TemplateBinding Border.CornerRadius}">
-                            <Grid HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" VerticalAlignment="{TemplateBinding VerticalContentAlignment}">
-                                <!--
-                                    Funky grid - because:
-                                    Chevron is over Presenter, ToggleButton is over Chevron, TextBox is over ToggleButton.
-                                    But, TextBox is not over Chevron, so ToggleButton still works.
-                                -->
-                                <Grid>
-                                    <Grid.ColumnDefinitions>
-                                        <ColumnDefinition Width="*" />
-                                        <ColumnDefinition Width="Auto" />
-                                    </Grid.ColumnDefinitions>
-                                    <Grid Grid.Column="0" Margin="{TemplateBinding Padding}">
-                                        <ContentPresenter
-                                            Name="PART_ContentPresenter"
-                                            HorizontalAlignment="Stretch"
-                                            VerticalAlignment="Stretch"
-                                            Content="{TemplateBinding SelectionBoxItem}"
-                                            ContentTemplate="{TemplateBinding SelectionBoxItemTemplate}"
-                                            ContentTemplateSelector="{TemplateBinding ItemTemplateSelector}"
-                                            ContentStringFormat="{TemplateBinding SelectionBoxItemStringFormat}"
-                                            SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"
-                                            IsHitTestVisible="False"
-                                            TextElement.Foreground="{TemplateBinding Foreground}" />
-                                    </Grid>
-                                    <Grid Grid.Column="1" Margin="{StaticResource ComboBoxChevronMargin}">
-                                        <TextBlock
-                                            x:Name="ChevronIcon"
-                                            Margin="0"
-                                            VerticalAlignment="Center"
-                                            FontSize="{StaticResource ComboBoxChevronSize}"
-                                            Foreground="{DynamicResource ComboBoxDropDownGlyphForeground}"
-                                            RenderTransformOrigin="0.5, 0.5"
-                                            FontFamily="{DynamicResource SymbolThemeFontFamily}"
-                                            Text ="{StaticResource ComboBoxChevronDownGlyph}">
-                                            <TextBlock.RenderTransform>
-                                                <RotateTransform Angle="0" />
-                                            </TextBlock.RenderTransform>
-                                        </TextBlock>
-                                    </Grid>
-                                    <Grid
-                                        Grid.Column="0"
-                                        Grid.ColumnSpan="2"
-                                        Margin="0">
-                                        <ToggleButton
-                                            Name="ToggleButton"
-                                            HorizontalAlignment="Stretch"
-                                            VerticalAlignment="Stretch"
-                                            ClickMode="Press"
-                                            Focusable="False"
-                                            Foreground="{TemplateBinding Foreground}"
-                                            IsChecked="{Binding Path=IsDropDownOpen, Mode=TwoWay, RelativeSource={RelativeSource TemplatedParent}}"
-                                            Style="{StaticResource DefaultComboBoxToggleButtonStyle}" />
-                                    </Grid>
-                                    <Grid Grid.Column="0" Margin="{TemplateBinding Padding}">
-                                        <TextBox
-                                            x:Name="PART_EditableTextBox"
-                                            HorizontalAlignment="Stretch"
-                                            VerticalAlignment="Stretch"
-                                            FontSize="{TemplateBinding FontSize}"
-                                            Foreground="{TemplateBinding Foreground}"
-                                            IsReadOnly="{TemplateBinding IsReadOnly}"
-                                            Style="{StaticResource DefaultComboBoxTextBoxStyle}"
-                                            AutomationProperties.Name="{TemplateBinding AutomationProperties.Name}" />
-                                    </Grid>
-                                </Grid>
-                                <Popup
-                                    x:Name="PART_Popup"
-                                    MinWidth="{TemplateBinding ActualWidth}"
-                                    VerticalAlignment="Center"
-                                    AllowsTransparency="True"
-                                    Focusable="False"
-                                    IsOpen="{TemplateBinding IsDropDownOpen}"
-                                    Placement="{TemplateBinding Popup.Placement}"
-                                    PopupAnimation="{TemplateBinding Popup.PopupAnimation}"
-                                    VerticalOffset="1">
-                                    <Border
-                                        x:Name="DropDownBorder"
-                                        Padding="0,4,0,6"
-                                        Background="{DynamicResource ComboBoxDropDownBackground}"
-                                        BorderBrush="{DynamicResource ComboBoxDropDownBorderBrush}"
-                                        BorderThickness="1.5"
-                                        CornerRadius="{DynamicResource PopupCornerRadius}"
-                                        SnapsToDevicePixels="True">
-                                        <!--Will revist this code while doing performance evaluation for dynamic resources.-->
-                                        <Border.RenderTransform>
-                                            <TranslateTransform />
-                                        </Border.RenderTransform>
-                                        <Grid>
-                                            <ScrollViewer
-                                                MaxHeight="{TemplateBinding MaxDropDownHeight}"
-                                                Margin="0"
-                                                HorizontalScrollBarVisibility="{TemplateBinding ScrollViewer.HorizontalScrollBarVisibility}"
-                                                SnapsToDevicePixels="True"
-                                                TextElement.FontSize="{TemplateBinding FontSize}"
-                                                TextElement.FontWeight="{TemplateBinding FontWeight}"
-                                                TextElement.Foreground="{TemplateBinding Foreground}"
-                                                VerticalScrollBarVisibility="{TemplateBinding ScrollViewer.VerticalScrollBarVisibility}">
-                                                <ItemsPresenter
-                                                    KeyboardNavigation.DirectionalNavigation="Contained"
-                                                    TextElement.FontSize="{TemplateBinding FontSize}" />
-                                            </ScrollViewer>
-                                        </Grid>
-                                        <Border.Effect>
-                                            <DropShadowEffect
-                                                BlurRadius="20"
-                                                Direction="270"
-                                                Opacity="0.25"
-                                                ShadowDepth="6"/>
-                                        </Border.Effect>
-                                    </Border>
-                                </Popup>
-                            </Grid>
-                        </Border>
-                        <Border
-                            x:Name="AccentBorder"
-                            HorizontalAlignment="Stretch"
-                            VerticalAlignment="Stretch"
-                            BorderBrush="{DynamicResource ComboBoxBorderBrushFocused}"
-                            BorderThickness="{StaticResource ComboBoxAccentBorderThemeThickness}"
-                            CornerRadius="{TemplateBinding Border.CornerRadius}"
-                            Visibility="Collapsed" />
-                    </Grid>
-                    <ControlTemplate.Triggers>
-                        <Trigger Property="IsDropDownOpen" Value="True">
-                            <Trigger.EnterActions>
-                                <BeginStoryboard>
-                                    <Storyboard>
-                                        <DoubleAnimation
-                                            Storyboard.TargetName="ChevronIcon"
-                                            Storyboard.TargetProperty="(TextBlock.RenderTransform).(RotateTransform.Angle)"
-                                            From="0"
-                                            To="180"
-                                            Duration="00:00:00.167" />
-                                        <DoubleAnimation
-                                            Storyboard.TargetName="DropDownBorder"
-                                            Storyboard.TargetProperty="(Border.RenderTransform).(TranslateTransform.Y)"
-                                            From="-90"
-                                            To="0"
-                                            Duration="00:00:00.167">
-                                            <DoubleAnimation.EasingFunction>
-                                                <CircleEase EasingMode="EaseOut" />
-                                            </DoubleAnimation.EasingFunction>
-                                        </DoubleAnimation>
-                                    </Storyboard>
-                                </BeginStoryboard>
-                            </Trigger.EnterActions>
-                            <Trigger.ExitActions>
-                                <BeginStoryboard>
-                                    <Storyboard>
-                                        <DoubleAnimation
-                                            Storyboard.TargetName="ChevronIcon"
-                                            Storyboard.TargetProperty="(TextBlock.RenderTransform).(RotateTransform.Angle)"
-                                            From="180"
-                                            To="0"
-                                            Duration="00:00:00.167" />
-                                    </Storyboard>
-                                </BeginStoryboard>
-                            </Trigger.ExitActions>
-                        </Trigger>
-                        <Trigger Property="HasItems" Value="False">
-                            <Setter TargetName="DropDownBorder" Property="MinHeight" Value="{StaticResource ComboBoxPopupMinHeight}" />
-                        </Trigger>
-                        <Trigger SourceName="PART_Popup" Property="Popup.AllowsTransparency" Value="False">
-                            <Setter TargetName="DropDownBorder" Property="CornerRadius" Value="0" />
-                        </Trigger>
-                        <Trigger Property="IsGrouping" Value="True">
-                            <Setter Property="ScrollViewer.CanContentScroll" Value="False" />
-                        </Trigger>
-                        <Trigger Property="IsEditable" Value="True">
-                            <Setter Property="IsTabStop" Value="False" />
-                            <Setter TargetName="PART_EditableTextBox" Property="Visibility" Value="Visible" />
-                            <Setter TargetName="PART_ContentPresenter" Property="Visibility" Value="Hidden" />
-                        </Trigger>
-                        <MultiTrigger>
-                            <MultiTrigger.Conditions>
-                                <Condition Property="IsEnabled" Value="True" />
-                                <Condition Property="IsKeyboardFocusWithin" Value="True" />
-                                <Condition Property="IsEditable" Value="True" />
-                            </MultiTrigger.Conditions>
-                            <Setter TargetName="ContentBorder" Property="Background" Value="{DynamicResource ComboBoxBackgroundFocused}" />
-                            <Setter TargetName="AccentBorder" Property="Visibility" Value="Visible" />
-                        </MultiTrigger>
-                        <MultiTrigger>
-                            <MultiTrigger.Conditions>
-                                <Condition Property="IsEnabled" Value="True" />
-                                <Condition Property="IsMouseOver" Value="True" />
-                                <Condition Property="IsKeyboardFocusWithin" Value="False" />
-                            </MultiTrigger.Conditions>
-                            <Setter TargetName="ContentBorder" Property="Background" Value="{DynamicResource ComboBoxBackgroundPointerOver}" />
-                        </MultiTrigger>
-                        <Trigger Property="IsEnabled" Value="False">
-                            <Setter TargetName="ContentBorder" Property="Background" Value="{DynamicResource ComboBoxBackgroundDisabled}" />
-                            <Setter TargetName="ContentBorder" Property="BorderBrush" Value="{DynamicResource ComboBoxBorderBrushDisabled}" />
-                            <Setter Property="Foreground" Value="{DynamicResource ComboBoxForegroundDisabled}" />
-                        </Trigger>
-                    </ControlTemplate.Triggers>
-                </ControlTemplate>
-            </Setter.Value>
-        </Setter>
+        <Setter Property="Template" Value="{StaticResource DefaultComboBoxTemplate}"/>
+        <Style.Triggers>
+            <Trigger Property="IsEditable" Value="True">
+                <Setter Property="Template" Value="{StaticResource EditableComboBoxTemplate}" />
+            </Trigger>
+        </Style.Triggers>
     </Style>
 
     <Style BasedOn="{StaticResource DefaultComboBoxItemStyle}" TargetType="{x:Type ComboBoxItem}" />
diff --git a/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.Dark.xaml b/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.Dark.xaml
index b4175efd69b..28c89caf450 100644
--- a/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.Dark.xaml
+++ b/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.Dark.xaml
@@ -77,8 +77,7 @@
   <Thickness x:Key="TimePickerHostPadding">0,1,0,2</Thickness>
   <Thickness x:Key="DatePickerHostPadding">0,1,0,2</Thickness>
   <Thickness x:Key="DatePickerHostMonthPadding">9,0,0,1</Thickness>
-  <Thickness x:Key="ComboBoxEditableTextPadding">10,0,30,0</Thickness>
-  <Thickness x:Key="TextControlErrorBorderPadding">1</Thickness>
+  <!-- <Thickness x:Key="ComboBoxEditableTextPadding">10,0,30,0</Thickness> -->
   <system:Double x:Key="ComboBoxMinHeight">24</system:Double>
   <!-- <Thickness x:Key="ComboBoxPadding">12,1,0,3</Thickness> -->
   <system:Double x:Key="NavigationViewItemOnLeftMinHeight">32</system:Double>
@@ -469,17 +468,43 @@
   <!--  TODO  -->
   <!--  ComboBox  -->
   <SolidColorBrush x:Key="ComboBoxBackground" Color="{StaticResource ControlFillColorDefault}" />
-  <SolidColorBrush x:Key="ComboBoxBackgroundFocused" Color="{StaticResource ControlFillColorDefault}" />
   <SolidColorBrush x:Key="ComboBoxBackgroundPointerOver" Color="{StaticResource ControlFillColorSecondary}" />
+  <SolidColorBrush x:Key="ComboBoxBackgroundPressed" Color="{StaticResource ControlFillColorTertiary}" />
   <SolidColorBrush x:Key="ComboBoxBackgroundDisabled" Color="{StaticResource ControlFillColorDisabled}" />
   <SolidColorBrush x:Key="ComboBoxForeground" Color="{StaticResource TextFillColorPrimary}" />
+  <SolidColorBrush x:Key="ComboBoxForegroundPointerOver" Color="{StaticResource TextFillColorPrimary}" />
+  <SolidColorBrush x:Key="ComboBoxForegroundPressed" Color="{StaticResource TextFillColorPrimary}" />
   <SolidColorBrush x:Key="ComboBoxForegroundDisabled" Color="{StaticResource TextFillColorDisabled}" />
-  <!--<SolidColorBrush x:Key="ComboBoxItemBorderBrush" Color="{StaticResource ControlElevationBorderBrush}" />-->
+  <SolidColorBrush x:Key="ComboBoxForegroundFocused" Color="{StaticResource TextFillColorPrimary}" />
+  <SolidColorBrush x:Key="ComboBoxForegroundFocusedPressed" Color="{StaticResource TextFillColorPrimary}" />
+  <LinearGradientBrush x:Key="ComboBoxBorderBrush" MappingMode="Absolute" StartPoint="0,0" EndPoint="0,3">
+    <LinearGradientBrush.GradientStops>
+      <GradientStop Offset="0.33" Color="{StaticResource ControlStrokeColorSecondary}" />
+      <GradientStop Offset="1.0" Color="{StaticResource ControlStrokeColorDefault}" />
+    </LinearGradientBrush.GradientStops>
+  </LinearGradientBrush>
+  <LinearGradientBrush x:Key="ComboBoxBorderBrushPointerOver" MappingMode="Absolute" StartPoint="0,0" EndPoint="0,3">
+    <LinearGradientBrush.GradientStops>
+      <GradientStop Offset="0.33" Color="{StaticResource ControlStrokeColorSecondary}" />
+      <GradientStop Offset="1.0" Color="{StaticResource ControlStrokeColorDefault}" />
+    </LinearGradientBrush.GradientStops>
+  </LinearGradientBrush>
+  <SolidColorBrush x:Key="ComboBoxBorderBrushPressed" Color="{StaticResource ControlStrokeColorDefault}" />
   <SolidColorBrush x:Key="ComboBoxBorderBrushDisabled" Color="{StaticResource ControlStrokeColorDefault}" />
-  <SolidColorBrush x:Key="ComboBoxBorderBrushFocused" Color="{StaticResource SystemAccentColorLight2}" />
   <SolidColorBrush x:Key="ComboBoxDropDownGlyphForeground" Color="{StaticResource TextFillColorSecondary}" />
+  <SolidColorBrush x:Key="ComboBoxDropDownGlyphForegroundFocused" Color="{StaticResource TextFillColorSecondary}" />
+  <SolidColorBrush x:Key="ComboBoxDropDownGlyphForegroundFocusedPressed" Color="{StaticResource TextFillColorSecondary}" />
+  <SolidColorBrush x:Key="ComboBoxDropDownGlyphForegroundDisabled" Color="{StaticResource TextFillColorDisabled}" />
+  <SolidColorBrush x:Key="ComboBoxDropDownForeground" Color="{StaticResource TextFillColorPrimary}" />
   <SolidColorBrush x:Key="ComboBoxDropDownBackground" Color="{StaticResource AcrylicBackgroundFillColorDefault}" />
   <SolidColorBrush x:Key="ComboBoxDropDownBorderBrush" Color="{StaticResource SurfaceStrokeColorFlyout}" />
+  <SolidColorBrush x:Key="ComboBoxDropDownBackgroundPointerOver" Color="{StaticResource SubtleFillColorSecondary}" />
+  <SolidColorBrush x:Key="ComboBoxDropDownBackgroundPointerPressed" Color="{StaticResource SubtleFillColorTertiary}" />
+  <SolidColorBrush x:Key="ComboBoxFocusedDropDownBackgroundPointerPressed" Color="{StaticResource ControlAltFillColorQuarternary}" />
+  <SolidColorBrush x:Key="ComboBoxEditableDropDownGlyphForeground" Color="{StaticResource TextFillColorSecondary}" />
+  <!-- Deprecated ComboBox brushes -->
+  <SolidColorBrush x:Key="ComboBoxBorderBrushFocused" Color="{StaticResource SystemAccentColorLight2}" />
+  <!--<SolidColorBrush x:Key="ComboBoxItemBorderBrush" Color="{StaticResource ControlElevationBorderBrush}" />-->
   <SolidColorBrush x:Key="ComboBoxItemPillFillBrush" Color="{StaticResource SystemAccentColorLight2}" />
   <SolidColorBrush x:Key="ComboBoxItemBackgroundSelected" Color="{StaticResource SubtleFillColorSecondary}" />
   <SolidColorBrush x:Key="ComboBoxItemForeground" Color="{StaticResource TextFillColorPrimary}" />
@@ -1399,49 +1424,78 @@
   <DataTemplate DataType="{x:Type CollectionViewGroup}">
     <ContentPresenter Content="{Binding Path=Name}" ContentStringFormat="{TemplateBinding ContentStringFormat}" />
   </DataTemplate>
-  <Thickness x:Key="ComboBoxPadding">10,8,10,8</Thickness>
-  <Thickness x:Key="ComboBoxBorderThemeThickness">1,1,1,1</Thickness>
+  <!-- Deprecated .NET 9 Keys -->
   <Thickness x:Key="ComboBoxAccentBorderThemeThickness">0,0,0,2</Thickness>
   <Thickness x:Key="ComboBoxChevronMargin">8,0,10,0</Thickness>
-  <Thickness x:Key="ComboBoxItemMargin">3,2,3,0</Thickness>
-  <Thickness x:Key="ComboBoxItemContentMargin">10,8,8,8</Thickness>
-  <system:Double x:Key="ComboBoxChevronSize">11.0</system:Double>
+  <!-- Redefined in .NET 10 -->
+  <!-- <Thickness x:Key="ComboBoxPadding">10,8,10,8</Thickness>
+            <system:Double x:Key="ComboBoxChevronSize">11</system:Double> -->
+  <Thickness x:Key="ComboBoxPadding">12,5,0,7</Thickness>
+  <Thickness x:Key="ComboBoxEditableTextPadding">11,5,38,6</Thickness>
+  <Thickness x:Key="ComboBoxBorderThemeThickness">1,1,1,1</Thickness>
+  <system:Double x:Key="ComboBoxChevronSize">10</system:Double>
   <system:Double x:Key="ComboBoxPopupMinHeight">32.0</system:Double>
   <system:String x:Key="ComboBoxChevronDownGlyph"></system:String>
+  <CornerRadius x:Key="ComboBoxDropDownButtonBackgroundCornerRadius">4</CornerRadius>
+  <Thickness x:Key="ComboBoxItemMargin">3,2,3,0</Thickness>
+  <Thickness x:Key="ComboBoxItemContentMargin">10,8,8,8</Thickness>
   <Style x:Key="DefaultComboBoxTextBoxStyle" TargetType="{x:Type TextBox}">
-    <!--  Focus by parent element  -->
     <Setter Property="FocusVisualStyle" Value="{x:Null}" />
-    <!--  Focus by parent element  -->
-    <!--  Universal WPF UI ContextMenu  -->
     <Setter Property="ContextMenu" Value="{DynamicResource DefaultControlContextMenu}" />
-    <!--  Universal WPF UI ContextMenu  -->
-    <Setter Property="Foreground" Value="{DynamicResource ComboBoxForeground}" />
-    <Setter Property="CaretBrush" Value="{DynamicResource ComboBoxForeground}" />
-    <Setter Property="Background" Value="Transparent" />
-    <Setter Property="Visibility" Value="Hidden" />
+    <Setter Property="Foreground" Value="{DynamicResource TextControlForeground}" />
+    <Setter Property="CaretBrush" Value="{DynamicResource TextControlForeground}" />
+    <Setter Property="BorderBrush" Value="{DynamicResource TextControlElevationBorderBrush}" />
+    <Setter Property="BorderThickness" Value="{StaticResource TextControlBorderThemeThickness}" />
+    <Setter Property="ScrollViewer.HorizontalScrollBarVisibility" Value="Hidden" />
+    <Setter Property="ScrollViewer.VerticalScrollBarVisibility" Value="Hidden" />
+    <Setter Property="HorizontalContentAlignment" Value="Left" />
+    <Setter Property="VerticalContentAlignment" Value="Top" />
     <Setter Property="Cursor" Value="IBeam" />
-    <Setter Property="Margin" Value="0" />
-    <Setter Property="Padding" Value="0" />
-    <Setter Property="SnapsToDevicePixels" Value="True" />
+    <Setter Property="MinHeight" Value="{DynamicResource TextBoxThemeMinHeight}" />
+    <Setter Property="MinWidth" Value="{DynamicResource TextControlThemeMinWidth}" />
+    <Setter Property="Padding" Value="{DynamicResource TextControlThemePadding}" />
+    <Setter Property="Border.CornerRadius" Value="{DynamicResource ControlCornerRadius}" />
+    <Setter Property="AllowDrop" Value="True" />
+    <Setter Property="ScrollViewer.PanningMode" Value="VerticalFirst" />
+    <Setter Property="Stylus.IsFlicksEnabled" Value="False" />
     <Setter Property="OverridesDefaultStyle" Value="True" />
+    <Setter Property="SelectionBrush" Value="{DynamicResource TextControlSelectionHighlightColor}" />
     <Setter Property="Template">
       <Setter.Value>
-        <ControlTemplate TargetType="{x:Type TextBox}">
-          <Decorator x:Name="PART_ContentHost" Margin="{TemplateBinding Padding}" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" TextElement.Foreground="{TemplateBinding Foreground}" />
+        <ControlTemplate TargetType="{x:Type TextBoxBase}">
+          <Grid>
+            <Border x:Name="ContentBorder" MinWidth="{TemplateBinding MinWidth}" MinHeight="{TemplateBinding MinHeight}" Background="{TemplateBinding Background}" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" CornerRadius="{TemplateBinding Border.CornerRadius}" />
+            <ScrollViewer x:Name="PART_ContentHost" Margin="{TemplateBinding BorderThickness}" CanContentScroll="{TemplateBinding ScrollViewer.CanContentScroll}" HorizontalScrollBarVisibility="{TemplateBinding ScrollViewer.HorizontalScrollBarVisibility}" IsDeferredScrollingEnabled="{TemplateBinding ScrollViewer.IsDeferredScrollingEnabled}" IsTabStop="{TemplateBinding ScrollViewer.IsTabStop}" Padding="{TemplateBinding Padding}" TextElement.Foreground="{TemplateBinding Foreground}" VerticalScrollBarVisibility="{TemplateBinding ScrollViewer.VerticalScrollBarVisibility}" />
+          </Grid>
+          <ControlTemplate.Triggers>
+            <Trigger Property="IsMouseOver" Value="True">
+              <!-- Disabling this trigger as this will be handled by the ComboBox style. -->
+              <!--<Setter TargetName="ContentBorder" Property="Background" Value="{DynamicResource TextControlBackgroundPointerOver}" />-->
+              <Setter TargetName="ContentBorder" Property="BorderBrush" Value="{DynamicResource TextControlBorderBrushPointerOver}" />
+              <Setter TargetName="PART_ContentHost" Property="Foreground" Value="{DynamicResource TextControlForegroundPointerOver}" />
+            </Trigger>
+            <Trigger Property="IsFocused" Value="True">
+              <Setter TargetName="ContentBorder" Property="BorderThickness" Value="{StaticResource TextControlBorderThemeThicknessFocused}" />
+              <Setter TargetName="ContentBorder" Property="Background" Value="{DynamicResource TextControlBackgroundFocused}" />
+              <Setter TargetName="ContentBorder" Property="BorderBrush" Value="{DynamicResource TextControlBorderBrushFocused}" />
+              <Setter TargetName="PART_ContentHost" Property="Foreground" Value="{DynamicResource TextControlForegroundFocused}" />
+            </Trigger>
+            <Trigger Property="IsEnabled" Value="False">
+              <Setter TargetName="ContentBorder" Property="Background" Value="{DynamicResource TextControlBackgroundDisabled}" />
+              <Setter TargetName="ContentBorder" Property="BorderBrush" Value="{DynamicResource TextControlBorderBrushDisabled}" />
+              <Setter TargetName="PART_ContentHost" Property="Foreground" Value="{DynamicResource TextControlForegroundDisabled}" />
+            </Trigger>
+          </ControlTemplate.Triggers>
         </ControlTemplate>
       </Setter.Value>
     </Setter>
   </Style>
   <Style x:Key="DefaultComboBoxToggleButtonStyle" TargetType="{x:Type ToggleButton}">
-    <!--  Focus by parent element  -->
     <Setter Property="FocusVisualStyle" Value="{x:Null}" />
-    <!--  Focus by parent element  -->
     <Setter Property="Foreground" Value="{DynamicResource ComboBoxForeground}" />
     <Setter Property="Background" Value="Transparent" />
     <Setter Property="BorderBrush" Value="Transparent" />
-    <Setter Property="BorderThickness" Value="0" />
-    <Setter Property="Border.CornerRadius" Value="0" />
-    <Setter Property="SnapsToDevicePixels" Value="True" />
+    <Setter Property="Border.CornerRadius" Value="{DynamicResource ControlCornerRadius}" />
     <Setter Property="OverridesDefaultStyle" Value="True" />
     <Setter Property="Template">
       <Setter.Value>
@@ -1491,14 +1545,217 @@
       </Setter.Value>
     </Setter>
   </Style>
+  <ControlTemplate x:Key="DefaultComboBoxTemplate" TargetType="{x:Type ComboBox}">
+    <Grid x:Name="LayoutGrid">
+      <Grid.ColumnDefinitions>
+        <ColumnDefinition Width="*" />
+        <ColumnDefinition Width="38" />
+      </Grid.ColumnDefinitions>
+      <Border x:Name="ContentBorder" Grid.ColumnSpan="2" Background="{TemplateBinding Background}" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" CornerRadius="{TemplateBinding Border.CornerRadius}" />
+      <ContentPresenter Name="PART_ContentPresenter" Content="{TemplateBinding SelectionBoxItem}" ContentTemplate="{TemplateBinding SelectionBoxItemTemplate}" ContentTemplateSelector="{TemplateBinding ItemTemplateSelector}" ContentStringFormat="{TemplateBinding SelectionBoxItemStringFormat}" Margin="{TemplateBinding Padding}" TextElement.Foreground="{TemplateBinding Foreground}" HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" VerticalAlignment="{TemplateBinding VerticalContentAlignment}" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" IsHitTestVisible="False" />
+      <ToggleButton x:Name="ToggleButton" Grid.ColumnSpan="2" Focusable="False" IsChecked="{Binding Path=IsDropDownOpen, Mode=TwoWay, RelativeSource={RelativeSource TemplatedParent}}" Style="{StaticResource DefaultComboBoxToggleButtonStyle}" />
+      <TextBlock x:Name="ChevronIcon" Grid.Column="1" HorizontalAlignment="Center" VerticalAlignment="Center" IsHitTestVisible="False" RenderTransformOrigin="0.5,0.5" FontFamily="{DynamicResource SymbolThemeFontFamily}" FontSize="{StaticResource ComboBoxChevronSize}" Text="{StaticResource ComboBoxChevronDownGlyph}">
+        <TextBlock.RenderTransform>
+          <RotateTransform Angle="0" />
+        </TextBlock.RenderTransform>
+      </TextBlock>
+      <Popup x:Name="PART_Popup" MinWidth="{TemplateBinding ActualWidth}" AllowsTransparency="True" Focusable="False" IsOpen="{TemplateBinding IsDropDownOpen}" Placement="{TemplateBinding Popup.Placement}" PopupAnimation="{TemplateBinding Popup.PopupAnimation}" VerticalOffset="1">
+        <Border x:Name="DropDownBorder" Padding="0,4,0,6" Background="{DynamicResource ComboBoxDropDownBackground}" BorderBrush="{DynamicResource ComboBoxDropDownBorderBrush}" BorderThickness="1.5" CornerRadius="{DynamicResource PopupCornerRadius}" SnapsToDevicePixels="True">
+          <Border.RenderTransform>
+            <TranslateTransform />
+          </Border.RenderTransform>
+          <Grid>
+            <ScrollViewer MaxHeight="{TemplateBinding MaxDropDownHeight}" SnapsToDevicePixels="True" HorizontalScrollBarVisibility="{TemplateBinding ScrollViewer.HorizontalScrollBarVisibility}" VerticalScrollBarVisibility="{TemplateBinding ScrollViewer.VerticalScrollBarVisibility}" TextElement.FontSize="{TemplateBinding FontSize}" TextElement.FontWeight="{TemplateBinding FontWeight}" TextElement.Foreground="{TemplateBinding Foreground}">
+              <StackPanel IsItemsHost="True" KeyboardNavigation.DirectionalNavigation="Contained" />
+            </ScrollViewer>
+          </Grid>
+          <Border.Effect>
+            <DropShadowEffect BlurRadius="20" Direction="270" Opacity="0.25" ShadowDepth="6" />
+          </Border.Effect>
+        </Border>
+      </Popup>
+    </Grid>
+    <ControlTemplate.Triggers>
+      <Trigger Property="IsDropDownOpen" Value="True">
+        <Trigger.EnterActions>
+          <BeginStoryboard>
+            <Storyboard>
+              <DoubleAnimation Storyboard.TargetName="ChevronIcon" Storyboard.TargetProperty="(TextBlock.RenderTransform).(RotateTransform.Angle)" From="0" To="180" Duration="00:00:00.167" />
+              <DoubleAnimation Storyboard.TargetName="DropDownBorder" Storyboard.TargetProperty="(Border.RenderTransform).(TranslateTransform.Y)" From="-90" To="0" Duration="00:00:00.167">
+                <DoubleAnimation.EasingFunction>
+                  <CircleEase EasingMode="EaseOut" />
+                </DoubleAnimation.EasingFunction>
+              </DoubleAnimation>
+            </Storyboard>
+          </BeginStoryboard>
+        </Trigger.EnterActions>
+        <Trigger.ExitActions>
+          <BeginStoryboard>
+            <Storyboard>
+              <DoubleAnimation Storyboard.TargetName="ChevronIcon" Storyboard.TargetProperty="(TextBlock.RenderTransform).(RotateTransform.Angle)" From="180" To="0" Duration="00:00:00.167" />
+            </Storyboard>
+          </BeginStoryboard>
+        </Trigger.ExitActions>
+      </Trigger>
+      <Trigger Property="HasItems" Value="False">
+        <Setter TargetName="DropDownBorder" Property="MinHeight" Value="{StaticResource ComboBoxPopupMinHeight}" />
+      </Trigger>
+      <Trigger SourceName="PART_Popup" Property="Popup.AllowsTransparency" Value="False">
+        <Setter TargetName="DropDownBorder" Property="CornerRadius" Value="0" />
+      </Trigger>
+      <Trigger Property="IsGrouping" Value="True">
+        <Setter Property="ScrollViewer.CanContentScroll" Value="False" />
+      </Trigger>
+      <!--PointerOver state-->
+      <Trigger Property="IsMouseOver" Value="True">
+        <Setter TargetName="ContentBorder" Property="Background" Value="{DynamicResource ComboBoxBackgroundPointerOver}" />
+        <Setter TargetName="ContentBorder" Property="BorderBrush" Value="{DynamicResource ComboBoxBorderBrushPointerOver}" />
+        <Setter TargetName="PART_ContentPresenter" Property="TextElement.Foreground" Value="{DynamicResource ComboBoxForegroundPointerOver}" />
+      </Trigger>
+      <!--Pressed state-->
+      <Trigger SourceName="ToggleButton" Property="IsPressed" Value="True">
+        <Setter TargetName="ContentBorder" Property="Background" Value="{DynamicResource ComboBoxBackgroundPressed}" />
+        <Setter TargetName="ContentBorder" Property="BorderBrush" Value="{DynamicResource ComboBoxBorderBrushPressed}" />
+        <Setter TargetName="PART_ContentPresenter" Property="TextElement.Foreground" Value="{DynamicResource ComboBoxForegroundPressed}" />
+      </Trigger>
+      <!--Focused state-->
+      <Trigger Property="IsFocused" Value="True">
+        <Setter TargetName="PART_ContentPresenter" Property="TextElement.Foreground" Value="{DynamicResource ComboBoxForegroundFocused}" />
+        <Setter TargetName="ChevronIcon" Property="Foreground" Value="{DynamicResource ComboBoxDropDownGlyphForegroundFocused}" />
+      </Trigger>
+      <!--FocusedPressed state-->
+      <MultiTrigger>
+        <MultiTrigger.Conditions>
+          <Condition Property="IsFocused" Value="True" />
+          <Condition SourceName="ToggleButton" Property="IsPressed" Value="True" />
+        </MultiTrigger.Conditions>
+        <Setter TargetName="PART_ContentPresenter" Property="TextElement.Foreground" Value="{DynamicResource ComboBoxForegroundFocusedPressed}" />
+        <Setter TargetName="ChevronIcon" Property="Foreground" Value="{DynamicResource ComboBoxDropDownGlyphForegroundFocusedPressed}" />
+      </MultiTrigger>
+      <!--Disabled state-->
+      <Trigger Property="IsEnabled" Value="False">
+        <Setter TargetName="ContentBorder" Property="Background" Value="{DynamicResource ComboBoxBackgroundDisabled}" />
+        <Setter TargetName="ContentBorder" Property="BorderBrush" Value="{DynamicResource ComboBoxBorderBrushDisabled}" />
+        <Setter TargetName="PART_ContentPresenter" Property="TextElement.Foreground" Value="{DynamicResource ComboBoxForegroundDisabled}" />
+        <Setter TargetName="ChevronIcon" Property="Foreground" Value="{DynamicResource ComboBoxDropDownGlyphForegroundDisabled}" />
+      </Trigger>
+    </ControlTemplate.Triggers>
+  </ControlTemplate>
+  <ControlTemplate x:Key="EditableComboBoxTemplate" TargetType="{x:Type ComboBox}">
+    <Grid x:Name="LayoutGrid">
+      <Grid.ColumnDefinitions>
+        <ColumnDefinition Width="*" />
+        <ColumnDefinition Width="38" />
+      </Grid.ColumnDefinitions>
+      <Border x:Name="ContentBorder" Grid.ColumnSpan="2" Background="{TemplateBinding Background}" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" CornerRadius="{TemplateBinding Border.CornerRadius}" />
+      <TextBox x:Name="PART_EditableTextBox" Grid.ColumnSpan="2" Padding="11,5,38,6" Foreground="{TemplateBinding Foreground}" FontSize="{TemplateBinding FontSize}" IsReadOnly="{TemplateBinding IsReadOnly}" Style="{StaticResource DefaultComboBoxTextBoxStyle}" AutomationProperties.Name="{TemplateBinding AutomationProperties.Name}" />
+      <Border x:Name="DropDownOverlay" Grid.Column="1" Margin="4" Width="30" Background="Transparent" CornerRadius="{StaticResource ComboBoxDropDownButtonBackgroundCornerRadius}" />
+      <ToggleButton x:Name="ToggleButton" Grid.Column="1" Margin="4" Focusable="False" IsChecked="{Binding Path=IsDropDownOpen, Mode=TwoWay, RelativeSource={RelativeSource TemplatedParent}}" Style="{StaticResource DefaultComboBoxToggleButtonStyle}" />
+      <TextBlock x:Name="ChevronIcon" Grid.Column="1" HorizontalAlignment="Center" VerticalAlignment="Center" IsHitTestVisible="False" RenderTransformOrigin="0.5,0.5" FontFamily="{DynamicResource SymbolThemeFontFamily}" FontSize="{StaticResource ComboBoxChevronSize}" Text="{StaticResource ComboBoxChevronDownGlyph}">
+        <TextBlock.RenderTransform>
+          <RotateTransform Angle="0" />
+        </TextBlock.RenderTransform>
+      </TextBlock>
+      <Popup x:Name="PART_Popup" Focusable="False" AllowsTransparency="True" MinWidth="{TemplateBinding ActualWidth}" IsOpen="{TemplateBinding IsDropDownOpen}" Placement="{TemplateBinding Popup.Placement}" PopupAnimation="{TemplateBinding Popup.PopupAnimation}" VerticalOffset="1">
+        <Border x:Name="DropDownBorder" Padding="0,4,0,6" BorderThickness="1.5" Background="{DynamicResource ComboBoxDropDownBackground}" BorderBrush="{DynamicResource ComboBoxDropDownBorderBrush}" CornerRadius="{DynamicResource PopupCornerRadius}" SnapsToDevicePixels="True">
+          <Border.RenderTransform>
+            <TranslateTransform />
+          </Border.RenderTransform>
+          <Grid>
+            <ScrollViewer MaxHeight="{TemplateBinding MaxDropDownHeight}" SnapsToDevicePixels="True" HorizontalScrollBarVisibility="{TemplateBinding ScrollViewer.HorizontalScrollBarVisibility}" VerticalScrollBarVisibility="{TemplateBinding ScrollViewer.VerticalScrollBarVisibility}" TextElement.FontSize="{TemplateBinding FontSize}" TextElement.FontWeight="{TemplateBinding FontWeight}" TextElement.Foreground="{TemplateBinding Foreground}">
+              <StackPanel IsItemsHost="True" KeyboardNavigation.DirectionalNavigation="Contained" />
+            </ScrollViewer>
+          </Grid>
+          <Border.Effect>
+            <DropShadowEffect BlurRadius="20" Direction="270" Opacity="0.25" ShadowDepth="6" />
+          </Border.Effect>
+        </Border>
+      </Popup>
+    </Grid>
+    <ControlTemplate.Triggers>
+      <Trigger Property="IsDropDownOpen" Value="True">
+        <Trigger.EnterActions>
+          <BeginStoryboard>
+            <Storyboard>
+              <DoubleAnimation Storyboard.TargetName="ChevronIcon" Storyboard.TargetProperty="(TextBlock.RenderTransform).(RotateTransform.Angle)" From="0" To="180" Duration="00:00:00.167" />
+              <DoubleAnimation Storyboard.TargetName="DropDownBorder" Storyboard.TargetProperty="(Border.RenderTransform).(TranslateTransform.Y)" From="-90" To="0" Duration="00:00:00.167">
+                <DoubleAnimation.EasingFunction>
+                  <CircleEase EasingMode="EaseOut" />
+                </DoubleAnimation.EasingFunction>
+              </DoubleAnimation>
+            </Storyboard>
+          </BeginStoryboard>
+        </Trigger.EnterActions>
+        <Trigger.ExitActions>
+          <BeginStoryboard>
+            <Storyboard>
+              <DoubleAnimation Storyboard.TargetName="ChevronIcon" Storyboard.TargetProperty="(TextBlock.RenderTransform).(RotateTransform.Angle)" From="180" To="0" Duration="00:00:00.167" />
+            </Storyboard>
+          </BeginStoryboard>
+        </Trigger.ExitActions>
+      </Trigger>
+      <Trigger Property="HasItems" Value="False">
+        <Setter TargetName="DropDownBorder" Property="MinHeight" Value="{StaticResource ComboBoxPopupMinHeight}" />
+      </Trigger>
+      <Trigger SourceName="PART_Popup" Property="Popup.AllowsTransparency" Value="False">
+        <Setter TargetName="DropDownBorder" Property="CornerRadius" Value="0" />
+      </Trigger>
+      <Trigger Property="IsGrouping" Value="True">
+        <Setter Property="ScrollViewer.CanContentScroll" Value="False" />
+      </Trigger>
+      <!-- PointerOver state-->
+      <Trigger Property="IsMouseOver" Value="True">
+        <Setter TargetName="ContentBorder" Property="Background" Value="{DynamicResource ComboBoxBackgroundPointerOver}" />
+        <Setter TargetName="ContentBorder" Property="BorderBrush" Value="{DynamicResource ComboBoxBorderBrushPointerOver}" />
+        <Setter TargetName="PART_EditableTextBox" Property="TextElement.Foreground" Value="{DynamicResource ComboBoxForegroundPointerOver}" />
+      </Trigger>
+      <!-- Focused / TextBoxFocused -->
+      <Trigger Property="IsFocused" Value="True">
+        <Setter TargetName="PART_EditableTextBox" Property="TextElement.Foreground" Value="{DynamicResource ComboBoxForegroundFocused}" />
+        <Setter TargetName="ChevronIcon" Property="Foreground" Value="{DynamicResource ComboBoxEditableDropDownGlyphForeground}" />
+      </Trigger>
+      <!--TextBoxOverlayPointerOver state-->
+      <Trigger SourceName="ToggleButton" Property="IsMouseOver" Value="True">
+        <Setter TargetName="DropDownOverlay" Property="Background" Value="{DynamicResource ComboBoxDropDownBackgroundPointerOver}" />
+      </Trigger>
+      <!--TextBoxOverlayPressed-->
+      <Trigger SourceName="ToggleButton" Property="IsPressed" Value="True">
+        <Setter TargetName="DropDownOverlay" Property="Background" Value="{DynamicResource ComboBoxDropDownBackgroundPointerPressed}" />
+      </Trigger>
+      <!--TextBoxFocusedOverlayPointerOver state-->
+      <MultiTrigger>
+        <MultiTrigger.Conditions>
+          <Condition Property="IsFocused" Value="True" />
+          <Condition SourceName="ToggleButton" Property="IsMouseOver" Value="True" />
+        </MultiTrigger.Conditions>
+        <Setter TargetName="DropDownOverlay" Property="Background" Value="{DynamicResource ComboBoxDropDownBackgroundPointerOver}" />
+        <Setter TargetName="ChevronIcon" Property="Foreground" Value="{DynamicResource ComboBoxEditableDropDownGlyphForeground}" />
+      </MultiTrigger>
+      <!-- FocusedPressed state / TextBoxFocusedOverlayPressed state -->
+      <MultiTrigger>
+        <MultiTrigger.Conditions>
+          <Condition Property="IsFocused" Value="True" />
+          <Condition SourceName="ToggleButton" Property="IsPressed" Value="True" />
+        </MultiTrigger.Conditions>
+        <Setter TargetName="ChevronIcon" Property="Foreground" Value="{DynamicResource ComboBoxEditableDropDownGlyphForeground}" />
+        <Setter TargetName="PART_EditableTextBox" Property="TextElement.Foreground" Value="{DynamicResource ComboBoxForegroundFocusedPressed}" />
+        <Setter TargetName="DropDownOverlay" Property="Background" Value="{DynamicResource ComboBoxFocusedDropDownBackgroundPointerPressed}" />
+      </MultiTrigger>
+      <!--Disabled state-->
+      <Trigger Property="IsEnabled" Value="False">
+        <Setter TargetName="ContentBorder" Property="Background" Value="{DynamicResource ComboBoxBackgroundDisabled}" />
+        <Setter TargetName="ContentBorder" Property="BorderBrush" Value="{DynamicResource ComboBoxBorderBrushDisabled}" />
+        <Setter TargetName="PART_EditableTextBox" Property="TextElement.Foreground" Value="{DynamicResource ComboBoxForegroundDisabled}" />
+        <Setter TargetName="ChevronIcon" Property="Foreground" Value="{DynamicResource ComboBoxDropDownGlyphForegroundDisabled}" />
+      </Trigger>
+    </ControlTemplate.Triggers>
+  </ControlTemplate>
   <Style x:Key="DefaultComboBoxStyle" TargetType="{x:Type ComboBox}">
-    <!--  Universal WPF UI focus  -->
     <Setter Property="FocusVisualStyle" Value="{DynamicResource DefaultControlFocusVisualStyle}" />
-    <!--  Universal WPF UI ContextMenu  -->
     <Setter Property="ContextMenu" Value="{DynamicResource DefaultControlContextMenu}" />
     <Setter Property="Foreground" Value="{DynamicResource ComboBoxForeground}" />
     <Setter Property="Background" Value="{DynamicResource ComboBoxBackground}" />
-    <Setter Property="BorderBrush" Value="{DynamicResource ControlElevationBorderBrush}" />
+    <Setter Property="BorderBrush" Value="{DynamicResource ComboBoxBorderBrush}" />
     <Setter Property="BorderThickness" Value="{StaticResource ComboBoxBorderThemeThickness}" />
     <Setter Property="ScrollViewer.CanContentScroll" Value="False" />
     <Setter Property="ScrollViewer.HorizontalScrollBarVisibility" Value="Auto" />
@@ -1513,125 +1770,15 @@
     <Setter Property="Padding" Value="{DynamicResource ComboBoxPadding}" />
     <Setter Property="Border.CornerRadius" Value="{DynamicResource ControlCornerRadius}" />
     <Setter Property="Popup.PopupAnimation" Value="None" />
-    <!--  WPF doesn't like centering, the animation is ugly and the mouse button sometimes clicks right away.  -->
     <Setter Property="Popup.Placement" Value="Bottom" />
     <Setter Property="SnapsToDevicePixels" Value="True" />
     <Setter Property="OverridesDefaultStyle" Value="True" />
-    <Setter Property="Template">
-      <Setter.Value>
-        <ControlTemplate TargetType="{x:Type ComboBox}">
-          <Grid>
-            <Border x:Name="ContentBorder" Grid.Row="0" MinWidth="{TemplateBinding MinWidth}" MinHeight="{TemplateBinding MinHeight}" Padding="0" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" Background="{TemplateBinding Background}" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" CornerRadius="{TemplateBinding Border.CornerRadius}">
-              <Grid HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" VerticalAlignment="{TemplateBinding VerticalContentAlignment}">
-                <!--
-                                    Funky grid - because:
-                                    Chevron is over Presenter, ToggleButton is over Chevron, TextBox is over ToggleButton.
-                                    But, TextBox is not over Chevron, so ToggleButton still works.
-                                -->
-                <Grid>
-                  <Grid.ColumnDefinitions>
-                    <ColumnDefinition Width="*" />
-                    <ColumnDefinition Width="Auto" />
-                  </Grid.ColumnDefinitions>
-                  <Grid Grid.Column="0" Margin="{TemplateBinding Padding}">
-                    <ContentPresenter Name="PART_ContentPresenter" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" Content="{TemplateBinding SelectionBoxItem}" ContentTemplate="{TemplateBinding SelectionBoxItemTemplate}" ContentTemplateSelector="{TemplateBinding ItemTemplateSelector}" ContentStringFormat="{TemplateBinding SelectionBoxItemStringFormat}" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" IsHitTestVisible="False" TextElement.Foreground="{TemplateBinding Foreground}" />
-                  </Grid>
-                  <Grid Grid.Column="1" Margin="{StaticResource ComboBoxChevronMargin}">
-                    <TextBlock x:Name="ChevronIcon" Margin="0" VerticalAlignment="Center" FontSize="{StaticResource ComboBoxChevronSize}" Foreground="{DynamicResource ComboBoxDropDownGlyphForeground}" RenderTransformOrigin="0.5, 0.5" FontFamily="{DynamicResource SymbolThemeFontFamily}" Text="{StaticResource ComboBoxChevronDownGlyph}">
-                      <TextBlock.RenderTransform>
-                        <RotateTransform Angle="0" />
-                      </TextBlock.RenderTransform>
-                    </TextBlock>
-                  </Grid>
-                  <Grid Grid.Column="0" Grid.ColumnSpan="2" Margin="0">
-                    <ToggleButton Name="ToggleButton" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" ClickMode="Press" Focusable="False" Foreground="{TemplateBinding Foreground}" IsChecked="{Binding Path=IsDropDownOpen, Mode=TwoWay, RelativeSource={RelativeSource TemplatedParent}}" Style="{StaticResource DefaultComboBoxToggleButtonStyle}" />
-                  </Grid>
-                  <Grid Grid.Column="0" Margin="{TemplateBinding Padding}">
-                    <TextBox x:Name="PART_EditableTextBox" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" FontSize="{TemplateBinding FontSize}" Foreground="{TemplateBinding Foreground}" IsReadOnly="{TemplateBinding IsReadOnly}" Style="{StaticResource DefaultComboBoxTextBoxStyle}" AutomationProperties.Name="{TemplateBinding AutomationProperties.Name}" />
-                  </Grid>
-                </Grid>
-                <Popup x:Name="PART_Popup" MinWidth="{TemplateBinding ActualWidth}" VerticalAlignment="Center" AllowsTransparency="True" Focusable="False" IsOpen="{TemplateBinding IsDropDownOpen}" Placement="{TemplateBinding Popup.Placement}" PopupAnimation="{TemplateBinding Popup.PopupAnimation}" VerticalOffset="1">
-                  <Border x:Name="DropDownBorder" Padding="0,4,0,6" Background="{DynamicResource ComboBoxDropDownBackground}" BorderBrush="{DynamicResource ComboBoxDropDownBorderBrush}" BorderThickness="1.5" CornerRadius="{DynamicResource PopupCornerRadius}" SnapsToDevicePixels="True">
-                    <!--Will revist this code while doing performance evaluation for dynamic resources.-->
-                    <Border.RenderTransform>
-                      <TranslateTransform />
-                    </Border.RenderTransform>
-                    <Grid>
-                      <ScrollViewer MaxHeight="{TemplateBinding MaxDropDownHeight}" Margin="0" HorizontalScrollBarVisibility="{TemplateBinding ScrollViewer.HorizontalScrollBarVisibility}" SnapsToDevicePixels="True" TextElement.FontSize="{TemplateBinding FontSize}" TextElement.FontWeight="{TemplateBinding FontWeight}" TextElement.Foreground="{TemplateBinding Foreground}" VerticalScrollBarVisibility="{TemplateBinding ScrollViewer.VerticalScrollBarVisibility}">
-                        <ItemsPresenter KeyboardNavigation.DirectionalNavigation="Contained" TextElement.FontSize="{TemplateBinding FontSize}" />
-                      </ScrollViewer>
-                    </Grid>
-                    <Border.Effect>
-                      <DropShadowEffect BlurRadius="20" Direction="270" Opacity="0.25" ShadowDepth="6" />
-                    </Border.Effect>
-                  </Border>
-                </Popup>
-              </Grid>
-            </Border>
-            <Border x:Name="AccentBorder" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" BorderBrush="{DynamicResource ComboBoxBorderBrushFocused}" BorderThickness="{StaticResource ComboBoxAccentBorderThemeThickness}" CornerRadius="{TemplateBinding Border.CornerRadius}" Visibility="Collapsed" />
-          </Grid>
-          <ControlTemplate.Triggers>
-            <Trigger Property="IsDropDownOpen" Value="True">
-              <Trigger.EnterActions>
-                <BeginStoryboard>
-                  <Storyboard>
-                    <DoubleAnimation Storyboard.TargetName="ChevronIcon" Storyboard.TargetProperty="(TextBlock.RenderTransform).(RotateTransform.Angle)" From="0" To="180" Duration="00:00:00.167" />
-                    <DoubleAnimation Storyboard.TargetName="DropDownBorder" Storyboard.TargetProperty="(Border.RenderTransform).(TranslateTransform.Y)" From="-90" To="0" Duration="00:00:00.167">
-                      <DoubleAnimation.EasingFunction>
-                        <CircleEase EasingMode="EaseOut" />
-                      </DoubleAnimation.EasingFunction>
-                    </DoubleAnimation>
-                  </Storyboard>
-                </BeginStoryboard>
-              </Trigger.EnterActions>
-              <Trigger.ExitActions>
-                <BeginStoryboard>
-                  <Storyboard>
-                    <DoubleAnimation Storyboard.TargetName="ChevronIcon" Storyboard.TargetProperty="(TextBlock.RenderTransform).(RotateTransform.Angle)" From="180" To="0" Duration="00:00:00.167" />
-                  </Storyboard>
-                </BeginStoryboard>
-              </Trigger.ExitActions>
-            </Trigger>
-            <Trigger Property="HasItems" Value="False">
-              <Setter TargetName="DropDownBorder" Property="MinHeight" Value="{StaticResource ComboBoxPopupMinHeight}" />
-            </Trigger>
-            <Trigger SourceName="PART_Popup" Property="Popup.AllowsTransparency" Value="False">
-              <Setter TargetName="DropDownBorder" Property="CornerRadius" Value="0" />
-            </Trigger>
-            <Trigger Property="IsGrouping" Value="True">
-              <Setter Property="ScrollViewer.CanContentScroll" Value="False" />
-            </Trigger>
-            <Trigger Property="IsEditable" Value="True">
-              <Setter Property="IsTabStop" Value="False" />
-              <Setter TargetName="PART_EditableTextBox" Property="Visibility" Value="Visible" />
-              <Setter TargetName="PART_ContentPresenter" Property="Visibility" Value="Hidden" />
-            </Trigger>
-            <MultiTrigger>
-              <MultiTrigger.Conditions>
-                <Condition Property="IsEnabled" Value="True" />
-                <Condition Property="IsKeyboardFocusWithin" Value="True" />
-                <Condition Property="IsEditable" Value="True" />
-              </MultiTrigger.Conditions>
-              <Setter TargetName="ContentBorder" Property="Background" Value="{DynamicResource ComboBoxBackgroundFocused}" />
-              <Setter TargetName="AccentBorder" Property="Visibility" Value="Visible" />
-            </MultiTrigger>
-            <MultiTrigger>
-              <MultiTrigger.Conditions>
-                <Condition Property="IsEnabled" Value="True" />
-                <Condition Property="IsMouseOver" Value="True" />
-                <Condition Property="IsKeyboardFocusWithin" Value="False" />
-              </MultiTrigger.Conditions>
-              <Setter TargetName="ContentBorder" Property="Background" Value="{DynamicResource ComboBoxBackgroundPointerOver}" />
-            </MultiTrigger>
-            <Trigger Property="IsEnabled" Value="False">
-              <Setter TargetName="ContentBorder" Property="Background" Value="{DynamicResource ComboBoxBackgroundDisabled}" />
-              <Setter TargetName="ContentBorder" Property="BorderBrush" Value="{DynamicResource ComboBoxBorderBrushDisabled}" />
-              <Setter Property="Foreground" Value="{DynamicResource ComboBoxForegroundDisabled}" />
-            </Trigger>
-          </ControlTemplate.Triggers>
-        </ControlTemplate>
-      </Setter.Value>
-    </Setter>
+    <Setter Property="Template" Value="{StaticResource DefaultComboBoxTemplate}" />
+    <Style.Triggers>
+      <Trigger Property="IsEditable" Value="True">
+        <Setter Property="Template" Value="{StaticResource EditableComboBoxTemplate}" />
+      </Trigger>
+    </Style.Triggers>
   </Style>
   <Style BasedOn="{StaticResource DefaultComboBoxItemStyle}" TargetType="{x:Type ComboBoxItem}" />
   <Style BasedOn="{StaticResource DefaultComboBoxStyle}" TargetType="{x:Type ComboBox}" />
diff --git a/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.HC.xaml b/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.HC.xaml
index b1e43a0f847..d97649a0b0c 100644
--- a/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.HC.xaml
+++ b/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.HC.xaml
@@ -77,8 +77,7 @@
   <Thickness x:Key="TimePickerHostPadding">0,1,0,2</Thickness>
   <Thickness x:Key="DatePickerHostPadding">0,1,0,2</Thickness>
   <Thickness x:Key="DatePickerHostMonthPadding">9,0,0,1</Thickness>
-  <Thickness x:Key="ComboBoxEditableTextPadding">10,0,30,0</Thickness>
-  <Thickness x:Key="TextControlErrorBorderPadding">1</Thickness>
+  <!-- <Thickness x:Key="ComboBoxEditableTextPadding">10,0,30,0</Thickness> -->
   <system:Double x:Key="ComboBoxMinHeight">24</system:Double>
   <!-- <Thickness x:Key="ComboBoxPadding">12,1,0,3</Thickness> -->
   <system:Double x:Key="NavigationViewItemOnLeftMinHeight">32</system:Double>
@@ -326,17 +325,33 @@
   <!--  TODO  -->
   <!--  ComboBox  -->
   <SolidColorBrush x:Key="ComboBoxBackground" Color="{StaticResource SystemColorButtonFaceColor}" />
-  <SolidColorBrush x:Key="ComboBoxBackgroundFocused" Color="{StaticResource SystemColorHighlightTextColor}" />
-  <SolidColorBrush x:Key="ComboBoxBackgroundPointerOver" Color="{StaticResource SystemColorHighlightTextColor}" />
-  <SolidColorBrush x:Key="ComboBoxBackgroundDisabled" Color="{StaticResource SystemColorWindowColor}" />
+  <SolidColorBrush x:Key="ComboBoxBackgroundPointerOver" Color="{StaticResource SystemColorWindowColor}" />
+  <SolidColorBrush x:Key="ComboBoxBackgroundPressed" Color="{StaticResource SystemColorButtonFaceColor}" />
+  <SolidColorBrush x:Key="ComboBoxBackgroundDisabled" Color="{StaticResource SystemColorButtonFaceColor}" />
   <SolidColorBrush x:Key="ComboBoxForeground" Color="{StaticResource SystemColorButtonTextColor}" />
+  <SolidColorBrush x:Key="ComboBoxForegroundPointerOver" Color="{StaticResource SystemColorButtonTextColor}" />
+  <SolidColorBrush x:Key="ComboBoxForegroundPressed" Color="{StaticResource SystemColorButtonTextColor}" />
   <SolidColorBrush x:Key="ComboBoxForegroundDisabled" Color="{StaticResource SystemColorGrayTextColor}" />
-  <!--<SolidColorBrush x:Key="ComboBoxItemBorderBrush" Color="{StaticResource ControlElevationBorderBrush}" />-->
-  <SolidColorBrush x:Key="ComboBoxBorderBrushDisabled" Color="{StaticResource SystemColorWindowColor}" />
+  <SolidColorBrush x:Key="ComboBoxForegroundFocused" Color="{StaticResource SystemColorButtonTextColor}" />
+  <SolidColorBrush x:Key="ComboBoxForegroundFocusedPressed" Color="{StaticResource SystemColorButtonTextColor}" />
+  <SolidColorBrush x:Key="ComboBoxBorderBrush" Color="{StaticResource SystemColorButtonTextColor}" />
+  <SolidColorBrush x:Key="ComboBoxBorderBrushPointerOver" Color="{StaticResource SystemColorHighlightColor}" />
+  <SolidColorBrush x:Key="ComboBoxBorderBrushPressed" Color="{StaticResource SystemColorHighlightColor}" />
+  <SolidColorBrush x:Key="ComboBoxBorderBrushDisabled" Color="{StaticResource SystemColorGrayTextColor}" />
+  <SolidColorBrush x:Key="ComboBoxDropDownGlyphForeground" Color="{StaticResource SystemColorButtonTextColor}" />
+  <SolidColorBrush x:Key="ComboBoxDropDownGlyphForegroundFocused" Color="{StaticResource SystemColorButtonTextColor}" />
+  <SolidColorBrush x:Key="ComboBoxDropDownGlyphForegroundFocusedPressed" Color="{StaticResource SystemColorButtonTextColor}" />
+  <SolidColorBrush x:Key="ComboBoxDropDownGlyphForegroundDisabled" Color="{StaticResource SystemColorGrayTextColor}" />
+  <SolidColorBrush x:Key="ComboBoxDropDownForeground" Color="{StaticResource SystemColorButtonTextColor}" />
+  <SolidColorBrush x:Key="ComboBoxDropDownBackground" Color="{StaticResource SystemColorButtonFaceColor}" />
+  <SolidColorBrush x:Key="ComboBoxDropDownBorderBrush" Color="{StaticResource SystemColorButtonTextColor}" />
+  <SolidColorBrush x:Key="ComboBoxDropDownBackgroundPointerOver" Color="{StaticResource SystemColorWindowColor}" />
+  <SolidColorBrush x:Key="ComboBoxDropDownBackgroundPointerPressed" Color="{StaticResource SystemColorButtonFaceColor}" />
+  <SolidColorBrush x:Key="ComboBoxFocusedDropDownBackgroundPointerPressed" Color="{StaticResource SystemColorButtonFaceColor}" />
+  <SolidColorBrush x:Key="ComboBoxEditableDropDownGlyphForeground" Color="{StaticResource SystemColorButtonTextColor}" />
+  <!-- Deprecated ComboBox brushes -->
   <SolidColorBrush x:Key="ComboBoxBorderBrushFocused" Color="{StaticResource SystemColorHighlightTextColor}" />
-  <SolidColorBrush x:Key="ComboBoxDropDownGlyphForeground" Color="{StaticResource SystemColorGrayTextColor}" />
-  <SolidColorBrush x:Key="ComboBoxDropDownBackground" Color="{StaticResource SystemColorWindowColor}" />
-  <SolidColorBrush x:Key="ComboBoxDropDownBorderBrush" Color="{StaticResource SystemColorWindowTextColor}" />
+  <!--<SolidColorBrush x:Key="ComboBoxItemBorderBrush" Color="{StaticResource ControlElevationBorderBrush}" />-->
   <SolidColorBrush x:Key="ComboBoxItemPillFillBrush" Color="{StaticResource SystemColorHighlightColor}" />
   <SolidColorBrush x:Key="ComboBoxItemBackgroundSelected" Color="{StaticResource SystemColorWindowColor}" />
   <SolidColorBrush x:Key="ComboBoxItemForeground" Color="{StaticResource SystemColorButtonTextColor}" />
@@ -1312,49 +1327,78 @@
   <DataTemplate DataType="{x:Type CollectionViewGroup}">
     <ContentPresenter Content="{Binding Path=Name}" ContentStringFormat="{TemplateBinding ContentStringFormat}" />
   </DataTemplate>
-  <Thickness x:Key="ComboBoxPadding">10,8,10,8</Thickness>
-  <Thickness x:Key="ComboBoxBorderThemeThickness">1,1,1,1</Thickness>
+  <!-- Deprecated .NET 9 Keys -->
   <Thickness x:Key="ComboBoxAccentBorderThemeThickness">0,0,0,2</Thickness>
   <Thickness x:Key="ComboBoxChevronMargin">8,0,10,0</Thickness>
-  <Thickness x:Key="ComboBoxItemMargin">3,2,3,0</Thickness>
-  <Thickness x:Key="ComboBoxItemContentMargin">10,8,8,8</Thickness>
-  <system:Double x:Key="ComboBoxChevronSize">11.0</system:Double>
+  <!-- Redefined in .NET 10 -->
+  <!-- <Thickness x:Key="ComboBoxPadding">10,8,10,8</Thickness>
+            <system:Double x:Key="ComboBoxChevronSize">11</system:Double> -->
+  <Thickness x:Key="ComboBoxPadding">12,5,0,7</Thickness>
+  <Thickness x:Key="ComboBoxEditableTextPadding">11,5,38,6</Thickness>
+  <Thickness x:Key="ComboBoxBorderThemeThickness">1,1,1,1</Thickness>
+  <system:Double x:Key="ComboBoxChevronSize">10</system:Double>
   <system:Double x:Key="ComboBoxPopupMinHeight">32.0</system:Double>
   <system:String x:Key="ComboBoxChevronDownGlyph"></system:String>
+  <CornerRadius x:Key="ComboBoxDropDownButtonBackgroundCornerRadius">4</CornerRadius>
+  <Thickness x:Key="ComboBoxItemMargin">3,2,3,0</Thickness>
+  <Thickness x:Key="ComboBoxItemContentMargin">10,8,8,8</Thickness>
   <Style x:Key="DefaultComboBoxTextBoxStyle" TargetType="{x:Type TextBox}">
-    <!--  Focus by parent element  -->
     <Setter Property="FocusVisualStyle" Value="{x:Null}" />
-    <!--  Focus by parent element  -->
-    <!--  Universal WPF UI ContextMenu  -->
     <Setter Property="ContextMenu" Value="{DynamicResource DefaultControlContextMenu}" />
-    <!--  Universal WPF UI ContextMenu  -->
-    <Setter Property="Foreground" Value="{DynamicResource ComboBoxForeground}" />
-    <Setter Property="CaretBrush" Value="{DynamicResource ComboBoxForeground}" />
-    <Setter Property="Background" Value="Transparent" />
-    <Setter Property="Visibility" Value="Hidden" />
+    <Setter Property="Foreground" Value="{DynamicResource TextControlForeground}" />
+    <Setter Property="CaretBrush" Value="{DynamicResource TextControlForeground}" />
+    <Setter Property="BorderBrush" Value="{DynamicResource TextControlElevationBorderBrush}" />
+    <Setter Property="BorderThickness" Value="{StaticResource TextControlBorderThemeThickness}" />
+    <Setter Property="ScrollViewer.HorizontalScrollBarVisibility" Value="Hidden" />
+    <Setter Property="ScrollViewer.VerticalScrollBarVisibility" Value="Hidden" />
+    <Setter Property="HorizontalContentAlignment" Value="Left" />
+    <Setter Property="VerticalContentAlignment" Value="Top" />
     <Setter Property="Cursor" Value="IBeam" />
-    <Setter Property="Margin" Value="0" />
-    <Setter Property="Padding" Value="0" />
-    <Setter Property="SnapsToDevicePixels" Value="True" />
+    <Setter Property="MinHeight" Value="{DynamicResource TextBoxThemeMinHeight}" />
+    <Setter Property="MinWidth" Value="{DynamicResource TextControlThemeMinWidth}" />
+    <Setter Property="Padding" Value="{DynamicResource TextControlThemePadding}" />
+    <Setter Property="Border.CornerRadius" Value="{DynamicResource ControlCornerRadius}" />
+    <Setter Property="AllowDrop" Value="True" />
+    <Setter Property="ScrollViewer.PanningMode" Value="VerticalFirst" />
+    <Setter Property="Stylus.IsFlicksEnabled" Value="False" />
     <Setter Property="OverridesDefaultStyle" Value="True" />
+    <Setter Property="SelectionBrush" Value="{DynamicResource TextControlSelectionHighlightColor}" />
     <Setter Property="Template">
       <Setter.Value>
-        <ControlTemplate TargetType="{x:Type TextBox}">
-          <Decorator x:Name="PART_ContentHost" Margin="{TemplateBinding Padding}" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" TextElement.Foreground="{TemplateBinding Foreground}" />
+        <ControlTemplate TargetType="{x:Type TextBoxBase}">
+          <Grid>
+            <Border x:Name="ContentBorder" MinWidth="{TemplateBinding MinWidth}" MinHeight="{TemplateBinding MinHeight}" Background="{TemplateBinding Background}" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" CornerRadius="{TemplateBinding Border.CornerRadius}" />
+            <ScrollViewer x:Name="PART_ContentHost" Margin="{TemplateBinding BorderThickness}" CanContentScroll="{TemplateBinding ScrollViewer.CanContentScroll}" HorizontalScrollBarVisibility="{TemplateBinding ScrollViewer.HorizontalScrollBarVisibility}" IsDeferredScrollingEnabled="{TemplateBinding ScrollViewer.IsDeferredScrollingEnabled}" IsTabStop="{TemplateBinding ScrollViewer.IsTabStop}" Padding="{TemplateBinding Padding}" TextElement.Foreground="{TemplateBinding Foreground}" VerticalScrollBarVisibility="{TemplateBinding ScrollViewer.VerticalScrollBarVisibility}" />
+          </Grid>
+          <ControlTemplate.Triggers>
+            <Trigger Property="IsMouseOver" Value="True">
+              <!-- Disabling this trigger as this will be handled by the ComboBox style. -->
+              <!--<Setter TargetName="ContentBorder" Property="Background" Value="{DynamicResource TextControlBackgroundPointerOver}" />-->
+              <Setter TargetName="ContentBorder" Property="BorderBrush" Value="{DynamicResource TextControlBorderBrushPointerOver}" />
+              <Setter TargetName="PART_ContentHost" Property="Foreground" Value="{DynamicResource TextControlForegroundPointerOver}" />
+            </Trigger>
+            <Trigger Property="IsFocused" Value="True">
+              <Setter TargetName="ContentBorder" Property="BorderThickness" Value="{StaticResource TextControlBorderThemeThicknessFocused}" />
+              <Setter TargetName="ContentBorder" Property="Background" Value="{DynamicResource TextControlBackgroundFocused}" />
+              <Setter TargetName="ContentBorder" Property="BorderBrush" Value="{DynamicResource TextControlBorderBrushFocused}" />
+              <Setter TargetName="PART_ContentHost" Property="Foreground" Value="{DynamicResource TextControlForegroundFocused}" />
+            </Trigger>
+            <Trigger Property="IsEnabled" Value="False">
+              <Setter TargetName="ContentBorder" Property="Background" Value="{DynamicResource TextControlBackgroundDisabled}" />
+              <Setter TargetName="ContentBorder" Property="BorderBrush" Value="{DynamicResource TextControlBorderBrushDisabled}" />
+              <Setter TargetName="PART_ContentHost" Property="Foreground" Value="{DynamicResource TextControlForegroundDisabled}" />
+            </Trigger>
+          </ControlTemplate.Triggers>
         </ControlTemplate>
       </Setter.Value>
     </Setter>
   </Style>
   <Style x:Key="DefaultComboBoxToggleButtonStyle" TargetType="{x:Type ToggleButton}">
-    <!--  Focus by parent element  -->
     <Setter Property="FocusVisualStyle" Value="{x:Null}" />
-    <!--  Focus by parent element  -->
     <Setter Property="Foreground" Value="{DynamicResource ComboBoxForeground}" />
     <Setter Property="Background" Value="Transparent" />
     <Setter Property="BorderBrush" Value="Transparent" />
-    <Setter Property="BorderThickness" Value="0" />
-    <Setter Property="Border.CornerRadius" Value="0" />
-    <Setter Property="SnapsToDevicePixels" Value="True" />
+    <Setter Property="Border.CornerRadius" Value="{DynamicResource ControlCornerRadius}" />
     <Setter Property="OverridesDefaultStyle" Value="True" />
     <Setter Property="Template">
       <Setter.Value>
@@ -1404,14 +1448,217 @@
       </Setter.Value>
     </Setter>
   </Style>
+  <ControlTemplate x:Key="DefaultComboBoxTemplate" TargetType="{x:Type ComboBox}">
+    <Grid x:Name="LayoutGrid">
+      <Grid.ColumnDefinitions>
+        <ColumnDefinition Width="*" />
+        <ColumnDefinition Width="38" />
+      </Grid.ColumnDefinitions>
+      <Border x:Name="ContentBorder" Grid.ColumnSpan="2" Background="{TemplateBinding Background}" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" CornerRadius="{TemplateBinding Border.CornerRadius}" />
+      <ContentPresenter Name="PART_ContentPresenter" Content="{TemplateBinding SelectionBoxItem}" ContentTemplate="{TemplateBinding SelectionBoxItemTemplate}" ContentTemplateSelector="{TemplateBinding ItemTemplateSelector}" ContentStringFormat="{TemplateBinding SelectionBoxItemStringFormat}" Margin="{TemplateBinding Padding}" TextElement.Foreground="{TemplateBinding Foreground}" HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" VerticalAlignment="{TemplateBinding VerticalContentAlignment}" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" IsHitTestVisible="False" />
+      <ToggleButton x:Name="ToggleButton" Grid.ColumnSpan="2" Focusable="False" IsChecked="{Binding Path=IsDropDownOpen, Mode=TwoWay, RelativeSource={RelativeSource TemplatedParent}}" Style="{StaticResource DefaultComboBoxToggleButtonStyle}" />
+      <TextBlock x:Name="ChevronIcon" Grid.Column="1" HorizontalAlignment="Center" VerticalAlignment="Center" IsHitTestVisible="False" RenderTransformOrigin="0.5,0.5" FontFamily="{DynamicResource SymbolThemeFontFamily}" FontSize="{StaticResource ComboBoxChevronSize}" Text="{StaticResource ComboBoxChevronDownGlyph}">
+        <TextBlock.RenderTransform>
+          <RotateTransform Angle="0" />
+        </TextBlock.RenderTransform>
+      </TextBlock>
+      <Popup x:Name="PART_Popup" MinWidth="{TemplateBinding ActualWidth}" AllowsTransparency="True" Focusable="False" IsOpen="{TemplateBinding IsDropDownOpen}" Placement="{TemplateBinding Popup.Placement}" PopupAnimation="{TemplateBinding Popup.PopupAnimation}" VerticalOffset="1">
+        <Border x:Name="DropDownBorder" Padding="0,4,0,6" Background="{DynamicResource ComboBoxDropDownBackground}" BorderBrush="{DynamicResource ComboBoxDropDownBorderBrush}" BorderThickness="1.5" CornerRadius="{DynamicResource PopupCornerRadius}" SnapsToDevicePixels="True">
+          <Border.RenderTransform>
+            <TranslateTransform />
+          </Border.RenderTransform>
+          <Grid>
+            <ScrollViewer MaxHeight="{TemplateBinding MaxDropDownHeight}" SnapsToDevicePixels="True" HorizontalScrollBarVisibility="{TemplateBinding ScrollViewer.HorizontalScrollBarVisibility}" VerticalScrollBarVisibility="{TemplateBinding ScrollViewer.VerticalScrollBarVisibility}" TextElement.FontSize="{TemplateBinding FontSize}" TextElement.FontWeight="{TemplateBinding FontWeight}" TextElement.Foreground="{TemplateBinding Foreground}">
+              <StackPanel IsItemsHost="True" KeyboardNavigation.DirectionalNavigation="Contained" />
+            </ScrollViewer>
+          </Grid>
+          <Border.Effect>
+            <DropShadowEffect BlurRadius="20" Direction="270" Opacity="0.25" ShadowDepth="6" />
+          </Border.Effect>
+        </Border>
+      </Popup>
+    </Grid>
+    <ControlTemplate.Triggers>
+      <Trigger Property="IsDropDownOpen" Value="True">
+        <Trigger.EnterActions>
+          <BeginStoryboard>
+            <Storyboard>
+              <DoubleAnimation Storyboard.TargetName="ChevronIcon" Storyboard.TargetProperty="(TextBlock.RenderTransform).(RotateTransform.Angle)" From="0" To="180" Duration="00:00:00.167" />
+              <DoubleAnimation Storyboard.TargetName="DropDownBorder" Storyboard.TargetProperty="(Border.RenderTransform).(TranslateTransform.Y)" From="-90" To="0" Duration="00:00:00.167">
+                <DoubleAnimation.EasingFunction>
+                  <CircleEase EasingMode="EaseOut" />
+                </DoubleAnimation.EasingFunction>
+              </DoubleAnimation>
+            </Storyboard>
+          </BeginStoryboard>
+        </Trigger.EnterActions>
+        <Trigger.ExitActions>
+          <BeginStoryboard>
+            <Storyboard>
+              <DoubleAnimation Storyboard.TargetName="ChevronIcon" Storyboard.TargetProperty="(TextBlock.RenderTransform).(RotateTransform.Angle)" From="180" To="0" Duration="00:00:00.167" />
+            </Storyboard>
+          </BeginStoryboard>
+        </Trigger.ExitActions>
+      </Trigger>
+      <Trigger Property="HasItems" Value="False">
+        <Setter TargetName="DropDownBorder" Property="MinHeight" Value="{StaticResource ComboBoxPopupMinHeight}" />
+      </Trigger>
+      <Trigger SourceName="PART_Popup" Property="Popup.AllowsTransparency" Value="False">
+        <Setter TargetName="DropDownBorder" Property="CornerRadius" Value="0" />
+      </Trigger>
+      <Trigger Property="IsGrouping" Value="True">
+        <Setter Property="ScrollViewer.CanContentScroll" Value="False" />
+      </Trigger>
+      <!--PointerOver state-->
+      <Trigger Property="IsMouseOver" Value="True">
+        <Setter TargetName="ContentBorder" Property="Background" Value="{DynamicResource ComboBoxBackgroundPointerOver}" />
+        <Setter TargetName="ContentBorder" Property="BorderBrush" Value="{DynamicResource ComboBoxBorderBrushPointerOver}" />
+        <Setter TargetName="PART_ContentPresenter" Property="TextElement.Foreground" Value="{DynamicResource ComboBoxForegroundPointerOver}" />
+      </Trigger>
+      <!--Pressed state-->
+      <Trigger SourceName="ToggleButton" Property="IsPressed" Value="True">
+        <Setter TargetName="ContentBorder" Property="Background" Value="{DynamicResource ComboBoxBackgroundPressed}" />
+        <Setter TargetName="ContentBorder" Property="BorderBrush" Value="{DynamicResource ComboBoxBorderBrushPressed}" />
+        <Setter TargetName="PART_ContentPresenter" Property="TextElement.Foreground" Value="{DynamicResource ComboBoxForegroundPressed}" />
+      </Trigger>
+      <!--Focused state-->
+      <Trigger Property="IsFocused" Value="True">
+        <Setter TargetName="PART_ContentPresenter" Property="TextElement.Foreground" Value="{DynamicResource ComboBoxForegroundFocused}" />
+        <Setter TargetName="ChevronIcon" Property="Foreground" Value="{DynamicResource ComboBoxDropDownGlyphForegroundFocused}" />
+      </Trigger>
+      <!--FocusedPressed state-->
+      <MultiTrigger>
+        <MultiTrigger.Conditions>
+          <Condition Property="IsFocused" Value="True" />
+          <Condition SourceName="ToggleButton" Property="IsPressed" Value="True" />
+        </MultiTrigger.Conditions>
+        <Setter TargetName="PART_ContentPresenter" Property="TextElement.Foreground" Value="{DynamicResource ComboBoxForegroundFocusedPressed}" />
+        <Setter TargetName="ChevronIcon" Property="Foreground" Value="{DynamicResource ComboBoxDropDownGlyphForegroundFocusedPressed}" />
+      </MultiTrigger>
+      <!--Disabled state-->
+      <Trigger Property="IsEnabled" Value="False">
+        <Setter TargetName="ContentBorder" Property="Background" Value="{DynamicResource ComboBoxBackgroundDisabled}" />
+        <Setter TargetName="ContentBorder" Property="BorderBrush" Value="{DynamicResource ComboBoxBorderBrushDisabled}" />
+        <Setter TargetName="PART_ContentPresenter" Property="TextElement.Foreground" Value="{DynamicResource ComboBoxForegroundDisabled}" />
+        <Setter TargetName="ChevronIcon" Property="Foreground" Value="{DynamicResource ComboBoxDropDownGlyphForegroundDisabled}" />
+      </Trigger>
+    </ControlTemplate.Triggers>
+  </ControlTemplate>
+  <ControlTemplate x:Key="EditableComboBoxTemplate" TargetType="{x:Type ComboBox}">
+    <Grid x:Name="LayoutGrid">
+      <Grid.ColumnDefinitions>
+        <ColumnDefinition Width="*" />
+        <ColumnDefinition Width="38" />
+      </Grid.ColumnDefinitions>
+      <Border x:Name="ContentBorder" Grid.ColumnSpan="2" Background="{TemplateBinding Background}" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" CornerRadius="{TemplateBinding Border.CornerRadius}" />
+      <TextBox x:Name="PART_EditableTextBox" Grid.ColumnSpan="2" Padding="11,5,38,6" Foreground="{TemplateBinding Foreground}" FontSize="{TemplateBinding FontSize}" IsReadOnly="{TemplateBinding IsReadOnly}" Style="{StaticResource DefaultComboBoxTextBoxStyle}" AutomationProperties.Name="{TemplateBinding AutomationProperties.Name}" />
+      <Border x:Name="DropDownOverlay" Grid.Column="1" Margin="4" Width="30" Background="Transparent" CornerRadius="{StaticResource ComboBoxDropDownButtonBackgroundCornerRadius}" />
+      <ToggleButton x:Name="ToggleButton" Grid.Column="1" Margin="4" Focusable="False" IsChecked="{Binding Path=IsDropDownOpen, Mode=TwoWay, RelativeSource={RelativeSource TemplatedParent}}" Style="{StaticResource DefaultComboBoxToggleButtonStyle}" />
+      <TextBlock x:Name="ChevronIcon" Grid.Column="1" HorizontalAlignment="Center" VerticalAlignment="Center" IsHitTestVisible="False" RenderTransformOrigin="0.5,0.5" FontFamily="{DynamicResource SymbolThemeFontFamily}" FontSize="{StaticResource ComboBoxChevronSize}" Text="{StaticResource ComboBoxChevronDownGlyph}">
+        <TextBlock.RenderTransform>
+          <RotateTransform Angle="0" />
+        </TextBlock.RenderTransform>
+      </TextBlock>
+      <Popup x:Name="PART_Popup" Focusable="False" AllowsTransparency="True" MinWidth="{TemplateBinding ActualWidth}" IsOpen="{TemplateBinding IsDropDownOpen}" Placement="{TemplateBinding Popup.Placement}" PopupAnimation="{TemplateBinding Popup.PopupAnimation}" VerticalOffset="1">
+        <Border x:Name="DropDownBorder" Padding="0,4,0,6" BorderThickness="1.5" Background="{DynamicResource ComboBoxDropDownBackground}" BorderBrush="{DynamicResource ComboBoxDropDownBorderBrush}" CornerRadius="{DynamicResource PopupCornerRadius}" SnapsToDevicePixels="True">
+          <Border.RenderTransform>
+            <TranslateTransform />
+          </Border.RenderTransform>
+          <Grid>
+            <ScrollViewer MaxHeight="{TemplateBinding MaxDropDownHeight}" SnapsToDevicePixels="True" HorizontalScrollBarVisibility="{TemplateBinding ScrollViewer.HorizontalScrollBarVisibility}" VerticalScrollBarVisibility="{TemplateBinding ScrollViewer.VerticalScrollBarVisibility}" TextElement.FontSize="{TemplateBinding FontSize}" TextElement.FontWeight="{TemplateBinding FontWeight}" TextElement.Foreground="{TemplateBinding Foreground}">
+              <StackPanel IsItemsHost="True" KeyboardNavigation.DirectionalNavigation="Contained" />
+            </ScrollViewer>
+          </Grid>
+          <Border.Effect>
+            <DropShadowEffect BlurRadius="20" Direction="270" Opacity="0.25" ShadowDepth="6" />
+          </Border.Effect>
+        </Border>
+      </Popup>
+    </Grid>
+    <ControlTemplate.Triggers>
+      <Trigger Property="IsDropDownOpen" Value="True">
+        <Trigger.EnterActions>
+          <BeginStoryboard>
+            <Storyboard>
+              <DoubleAnimation Storyboard.TargetName="ChevronIcon" Storyboard.TargetProperty="(TextBlock.RenderTransform).(RotateTransform.Angle)" From="0" To="180" Duration="00:00:00.167" />
+              <DoubleAnimation Storyboard.TargetName="DropDownBorder" Storyboard.TargetProperty="(Border.RenderTransform).(TranslateTransform.Y)" From="-90" To="0" Duration="00:00:00.167">
+                <DoubleAnimation.EasingFunction>
+                  <CircleEase EasingMode="EaseOut" />
+                </DoubleAnimation.EasingFunction>
+              </DoubleAnimation>
+            </Storyboard>
+          </BeginStoryboard>
+        </Trigger.EnterActions>
+        <Trigger.ExitActions>
+          <BeginStoryboard>
+            <Storyboard>
+              <DoubleAnimation Storyboard.TargetName="ChevronIcon" Storyboard.TargetProperty="(TextBlock.RenderTransform).(RotateTransform.Angle)" From="180" To="0" Duration="00:00:00.167" />
+            </Storyboard>
+          </BeginStoryboard>
+        </Trigger.ExitActions>
+      </Trigger>
+      <Trigger Property="HasItems" Value="False">
+        <Setter TargetName="DropDownBorder" Property="MinHeight" Value="{StaticResource ComboBoxPopupMinHeight}" />
+      </Trigger>
+      <Trigger SourceName="PART_Popup" Property="Popup.AllowsTransparency" Value="False">
+        <Setter TargetName="DropDownBorder" Property="CornerRadius" Value="0" />
+      </Trigger>
+      <Trigger Property="IsGrouping" Value="True">
+        <Setter Property="ScrollViewer.CanContentScroll" Value="False" />
+      </Trigger>
+      <!-- PointerOver state-->
+      <Trigger Property="IsMouseOver" Value="True">
+        <Setter TargetName="ContentBorder" Property="Background" Value="{DynamicResource ComboBoxBackgroundPointerOver}" />
+        <Setter TargetName="ContentBorder" Property="BorderBrush" Value="{DynamicResource ComboBoxBorderBrushPointerOver}" />
+        <Setter TargetName="PART_EditableTextBox" Property="TextElement.Foreground" Value="{DynamicResource ComboBoxForegroundPointerOver}" />
+      </Trigger>
+      <!-- Focused / TextBoxFocused -->
+      <Trigger Property="IsFocused" Value="True">
+        <Setter TargetName="PART_EditableTextBox" Property="TextElement.Foreground" Value="{DynamicResource ComboBoxForegroundFocused}" />
+        <Setter TargetName="ChevronIcon" Property="Foreground" Value="{DynamicResource ComboBoxEditableDropDownGlyphForeground}" />
+      </Trigger>
+      <!--TextBoxOverlayPointerOver state-->
+      <Trigger SourceName="ToggleButton" Property="IsMouseOver" Value="True">
+        <Setter TargetName="DropDownOverlay" Property="Background" Value="{DynamicResource ComboBoxDropDownBackgroundPointerOver}" />
+      </Trigger>
+      <!--TextBoxOverlayPressed-->
+      <Trigger SourceName="ToggleButton" Property="IsPressed" Value="True">
+        <Setter TargetName="DropDownOverlay" Property="Background" Value="{DynamicResource ComboBoxDropDownBackgroundPointerPressed}" />
+      </Trigger>
+      <!--TextBoxFocusedOverlayPointerOver state-->
+      <MultiTrigger>
+        <MultiTrigger.Conditions>
+          <Condition Property="IsFocused" Value="True" />
+          <Condition SourceName="ToggleButton" Property="IsMouseOver" Value="True" />
+        </MultiTrigger.Conditions>
+        <Setter TargetName="DropDownOverlay" Property="Background" Value="{DynamicResource ComboBoxDropDownBackgroundPointerOver}" />
+        <Setter TargetName="ChevronIcon" Property="Foreground" Value="{DynamicResource ComboBoxEditableDropDownGlyphForeground}" />
+      </MultiTrigger>
+      <!-- FocusedPressed state / TextBoxFocusedOverlayPressed state -->
+      <MultiTrigger>
+        <MultiTrigger.Conditions>
+          <Condition Property="IsFocused" Value="True" />
+          <Condition SourceName="ToggleButton" Property="IsPressed" Value="True" />
+        </MultiTrigger.Conditions>
+        <Setter TargetName="ChevronIcon" Property="Foreground" Value="{DynamicResource ComboBoxEditableDropDownGlyphForeground}" />
+        <Setter TargetName="PART_EditableTextBox" Property="TextElement.Foreground" Value="{DynamicResource ComboBoxForegroundFocusedPressed}" />
+        <Setter TargetName="DropDownOverlay" Property="Background" Value="{DynamicResource ComboBoxFocusedDropDownBackgroundPointerPressed}" />
+      </MultiTrigger>
+      <!--Disabled state-->
+      <Trigger Property="IsEnabled" Value="False">
+        <Setter TargetName="ContentBorder" Property="Background" Value="{DynamicResource ComboBoxBackgroundDisabled}" />
+        <Setter TargetName="ContentBorder" Property="BorderBrush" Value="{DynamicResource ComboBoxBorderBrushDisabled}" />
+        <Setter TargetName="PART_EditableTextBox" Property="TextElement.Foreground" Value="{DynamicResource ComboBoxForegroundDisabled}" />
+        <Setter TargetName="ChevronIcon" Property="Foreground" Value="{DynamicResource ComboBoxDropDownGlyphForegroundDisabled}" />
+      </Trigger>
+    </ControlTemplate.Triggers>
+  </ControlTemplate>
   <Style x:Key="DefaultComboBoxStyle" TargetType="{x:Type ComboBox}">
-    <!--  Universal WPF UI focus  -->
     <Setter Property="FocusVisualStyle" Value="{DynamicResource DefaultControlFocusVisualStyle}" />
-    <!--  Universal WPF UI ContextMenu  -->
     <Setter Property="ContextMenu" Value="{DynamicResource DefaultControlContextMenu}" />
     <Setter Property="Foreground" Value="{DynamicResource ComboBoxForeground}" />
     <Setter Property="Background" Value="{DynamicResource ComboBoxBackground}" />
-    <Setter Property="BorderBrush" Value="{DynamicResource ControlElevationBorderBrush}" />
+    <Setter Property="BorderBrush" Value="{DynamicResource ComboBoxBorderBrush}" />
     <Setter Property="BorderThickness" Value="{StaticResource ComboBoxBorderThemeThickness}" />
     <Setter Property="ScrollViewer.CanContentScroll" Value="False" />
     <Setter Property="ScrollViewer.HorizontalScrollBarVisibility" Value="Auto" />
@@ -1426,125 +1673,15 @@
     <Setter Property="Padding" Value="{DynamicResource ComboBoxPadding}" />
     <Setter Property="Border.CornerRadius" Value="{DynamicResource ControlCornerRadius}" />
     <Setter Property="Popup.PopupAnimation" Value="None" />
-    <!--  WPF doesn't like centering, the animation is ugly and the mouse button sometimes clicks right away.  -->
     <Setter Property="Popup.Placement" Value="Bottom" />
     <Setter Property="SnapsToDevicePixels" Value="True" />
     <Setter Property="OverridesDefaultStyle" Value="True" />
-    <Setter Property="Template">
-      <Setter.Value>
-        <ControlTemplate TargetType="{x:Type ComboBox}">
-          <Grid>
-            <Border x:Name="ContentBorder" Grid.Row="0" MinWidth="{TemplateBinding MinWidth}" MinHeight="{TemplateBinding MinHeight}" Padding="0" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" Background="{TemplateBinding Background}" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" CornerRadius="{TemplateBinding Border.CornerRadius}">
-              <Grid HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" VerticalAlignment="{TemplateBinding VerticalContentAlignment}">
-                <!--
-                                    Funky grid - because:
-                                    Chevron is over Presenter, ToggleButton is over Chevron, TextBox is over ToggleButton.
-                                    But, TextBox is not over Chevron, so ToggleButton still works.
-                                -->
-                <Grid>
-                  <Grid.ColumnDefinitions>
-                    <ColumnDefinition Width="*" />
-                    <ColumnDefinition Width="Auto" />
-                  </Grid.ColumnDefinitions>
-                  <Grid Grid.Column="0" Margin="{TemplateBinding Padding}">
-                    <ContentPresenter Name="PART_ContentPresenter" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" Content="{TemplateBinding SelectionBoxItem}" ContentTemplate="{TemplateBinding SelectionBoxItemTemplate}" ContentTemplateSelector="{TemplateBinding ItemTemplateSelector}" ContentStringFormat="{TemplateBinding SelectionBoxItemStringFormat}" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" IsHitTestVisible="False" TextElement.Foreground="{TemplateBinding Foreground}" />
-                  </Grid>
-                  <Grid Grid.Column="1" Margin="{StaticResource ComboBoxChevronMargin}">
-                    <TextBlock x:Name="ChevronIcon" Margin="0" VerticalAlignment="Center" FontSize="{StaticResource ComboBoxChevronSize}" Foreground="{DynamicResource ComboBoxDropDownGlyphForeground}" RenderTransformOrigin="0.5, 0.5" FontFamily="{DynamicResource SymbolThemeFontFamily}" Text="{StaticResource ComboBoxChevronDownGlyph}">
-                      <TextBlock.RenderTransform>
-                        <RotateTransform Angle="0" />
-                      </TextBlock.RenderTransform>
-                    </TextBlock>
-                  </Grid>
-                  <Grid Grid.Column="0" Grid.ColumnSpan="2" Margin="0">
-                    <ToggleButton Name="ToggleButton" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" ClickMode="Press" Focusable="False" Foreground="{TemplateBinding Foreground}" IsChecked="{Binding Path=IsDropDownOpen, Mode=TwoWay, RelativeSource={RelativeSource TemplatedParent}}" Style="{StaticResource DefaultComboBoxToggleButtonStyle}" />
-                  </Grid>
-                  <Grid Grid.Column="0" Margin="{TemplateBinding Padding}">
-                    <TextBox x:Name="PART_EditableTextBox" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" FontSize="{TemplateBinding FontSize}" Foreground="{TemplateBinding Foreground}" IsReadOnly="{TemplateBinding IsReadOnly}" Style="{StaticResource DefaultComboBoxTextBoxStyle}" AutomationProperties.Name="{TemplateBinding AutomationProperties.Name}" />
-                  </Grid>
-                </Grid>
-                <Popup x:Name="PART_Popup" MinWidth="{TemplateBinding ActualWidth}" VerticalAlignment="Center" AllowsTransparency="True" Focusable="False" IsOpen="{TemplateBinding IsDropDownOpen}" Placement="{TemplateBinding Popup.Placement}" PopupAnimation="{TemplateBinding Popup.PopupAnimation}" VerticalOffset="1">
-                  <Border x:Name="DropDownBorder" Padding="0,4,0,6" Background="{DynamicResource ComboBoxDropDownBackground}" BorderBrush="{DynamicResource ComboBoxDropDownBorderBrush}" BorderThickness="1.5" CornerRadius="{DynamicResource PopupCornerRadius}" SnapsToDevicePixels="True">
-                    <!--Will revist this code while doing performance evaluation for dynamic resources.-->
-                    <Border.RenderTransform>
-                      <TranslateTransform />
-                    </Border.RenderTransform>
-                    <Grid>
-                      <ScrollViewer MaxHeight="{TemplateBinding MaxDropDownHeight}" Margin="0" HorizontalScrollBarVisibility="{TemplateBinding ScrollViewer.HorizontalScrollBarVisibility}" SnapsToDevicePixels="True" TextElement.FontSize="{TemplateBinding FontSize}" TextElement.FontWeight="{TemplateBinding FontWeight}" TextElement.Foreground="{TemplateBinding Foreground}" VerticalScrollBarVisibility="{TemplateBinding ScrollViewer.VerticalScrollBarVisibility}">
-                        <ItemsPresenter KeyboardNavigation.DirectionalNavigation="Contained" TextElement.FontSize="{TemplateBinding FontSize}" />
-                      </ScrollViewer>
-                    </Grid>
-                    <Border.Effect>
-                      <DropShadowEffect BlurRadius="20" Direction="270" Opacity="0.25" ShadowDepth="6" />
-                    </Border.Effect>
-                  </Border>
-                </Popup>
-              </Grid>
-            </Border>
-            <Border x:Name="AccentBorder" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" BorderBrush="{DynamicResource ComboBoxBorderBrushFocused}" BorderThickness="{StaticResource ComboBoxAccentBorderThemeThickness}" CornerRadius="{TemplateBinding Border.CornerRadius}" Visibility="Collapsed" />
-          </Grid>
-          <ControlTemplate.Triggers>
-            <Trigger Property="IsDropDownOpen" Value="True">
-              <Trigger.EnterActions>
-                <BeginStoryboard>
-                  <Storyboard>
-                    <DoubleAnimation Storyboard.TargetName="ChevronIcon" Storyboard.TargetProperty="(TextBlock.RenderTransform).(RotateTransform.Angle)" From="0" To="180" Duration="00:00:00.167" />
-                    <DoubleAnimation Storyboard.TargetName="DropDownBorder" Storyboard.TargetProperty="(Border.RenderTransform).(TranslateTransform.Y)" From="-90" To="0" Duration="00:00:00.167">
-                      <DoubleAnimation.EasingFunction>
-                        <CircleEase EasingMode="EaseOut" />
-                      </DoubleAnimation.EasingFunction>
-                    </DoubleAnimation>
-                  </Storyboard>
-                </BeginStoryboard>
-              </Trigger.EnterActions>
-              <Trigger.ExitActions>
-                <BeginStoryboard>
-                  <Storyboard>
-                    <DoubleAnimation Storyboard.TargetName="ChevronIcon" Storyboard.TargetProperty="(TextBlock.RenderTransform).(RotateTransform.Angle)" From="180" To="0" Duration="00:00:00.167" />
-                  </Storyboard>
-                </BeginStoryboard>
-              </Trigger.ExitActions>
-            </Trigger>
-            <Trigger Property="HasItems" Value="False">
-              <Setter TargetName="DropDownBorder" Property="MinHeight" Value="{StaticResource ComboBoxPopupMinHeight}" />
-            </Trigger>
-            <Trigger SourceName="PART_Popup" Property="Popup.AllowsTransparency" Value="False">
-              <Setter TargetName="DropDownBorder" Property="CornerRadius" Value="0" />
-            </Trigger>
-            <Trigger Property="IsGrouping" Value="True">
-              <Setter Property="ScrollViewer.CanContentScroll" Value="False" />
-            </Trigger>
-            <Trigger Property="IsEditable" Value="True">
-              <Setter Property="IsTabStop" Value="False" />
-              <Setter TargetName="PART_EditableTextBox" Property="Visibility" Value="Visible" />
-              <Setter TargetName="PART_ContentPresenter" Property="Visibility" Value="Hidden" />
-            </Trigger>
-            <MultiTrigger>
-              <MultiTrigger.Conditions>
-                <Condition Property="IsEnabled" Value="True" />
-                <Condition Property="IsKeyboardFocusWithin" Value="True" />
-                <Condition Property="IsEditable" Value="True" />
-              </MultiTrigger.Conditions>
-              <Setter TargetName="ContentBorder" Property="Background" Value="{DynamicResource ComboBoxBackgroundFocused}" />
-              <Setter TargetName="AccentBorder" Property="Visibility" Value="Visible" />
-            </MultiTrigger>
-            <MultiTrigger>
-              <MultiTrigger.Conditions>
-                <Condition Property="IsEnabled" Value="True" />
-                <Condition Property="IsMouseOver" Value="True" />
-                <Condition Property="IsKeyboardFocusWithin" Value="False" />
-              </MultiTrigger.Conditions>
-              <Setter TargetName="ContentBorder" Property="Background" Value="{DynamicResource ComboBoxBackgroundPointerOver}" />
-            </MultiTrigger>
-            <Trigger Property="IsEnabled" Value="False">
-              <Setter TargetName="ContentBorder" Property="Background" Value="{DynamicResource ComboBoxBackgroundDisabled}" />
-              <Setter TargetName="ContentBorder" Property="BorderBrush" Value="{DynamicResource ComboBoxBorderBrushDisabled}" />
-              <Setter Property="Foreground" Value="{DynamicResource ComboBoxForegroundDisabled}" />
-            </Trigger>
-          </ControlTemplate.Triggers>
-        </ControlTemplate>
-      </Setter.Value>
-    </Setter>
+    <Setter Property="Template" Value="{StaticResource DefaultComboBoxTemplate}" />
+    <Style.Triggers>
+      <Trigger Property="IsEditable" Value="True">
+        <Setter Property="Template" Value="{StaticResource EditableComboBoxTemplate}" />
+      </Trigger>
+    </Style.Triggers>
   </Style>
   <Style BasedOn="{StaticResource DefaultComboBoxItemStyle}" TargetType="{x:Type ComboBoxItem}" />
   <Style BasedOn="{StaticResource DefaultComboBoxStyle}" TargetType="{x:Type ComboBox}" />
diff --git a/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.Light.xaml b/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.Light.xaml
index a6ea4974051..d3ff3fe18ee 100644
--- a/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.Light.xaml
+++ b/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.Light.xaml
@@ -77,8 +77,7 @@
   <Thickness x:Key="TimePickerHostPadding">0,1,0,2</Thickness>
   <Thickness x:Key="DatePickerHostPadding">0,1,0,2</Thickness>
   <Thickness x:Key="DatePickerHostMonthPadding">9,0,0,1</Thickness>
-  <Thickness x:Key="ComboBoxEditableTextPadding">10,0,30,0</Thickness>
-  <Thickness x:Key="TextControlErrorBorderPadding">1</Thickness>
+  <!-- <Thickness x:Key="ComboBoxEditableTextPadding">10,0,30,0</Thickness> -->
   <system:Double x:Key="ComboBoxMinHeight">24</system:Double>
   <!-- <Thickness x:Key="ComboBoxPadding">12,1,0,3</Thickness> -->
   <system:Double x:Key="NavigationViewItemOnLeftMinHeight">32</system:Double>
@@ -478,17 +477,49 @@
   <!--  TODO  -->
   <!--  ComboBox  -->
   <SolidColorBrush x:Key="ComboBoxBackground" Color="{StaticResource ControlFillColorDefault}" />
-  <SolidColorBrush x:Key="ComboBoxBackgroundFocused" Color="{StaticResource ControlFillColorDefault}" />
   <SolidColorBrush x:Key="ComboBoxBackgroundPointerOver" Color="{StaticResource ControlFillColorSecondary}" />
+  <SolidColorBrush x:Key="ComboBoxBackgroundPressed" Color="{StaticResource ControlFillColorTertiary}" />
   <SolidColorBrush x:Key="ComboBoxBackgroundDisabled" Color="{StaticResource ControlFillColorDisabled}" />
   <SolidColorBrush x:Key="ComboBoxForeground" Color="{StaticResource TextFillColorPrimary}" />
+  <SolidColorBrush x:Key="ComboBoxForegroundPointerOver" Color="{StaticResource TextFillColorPrimary}" />
+  <SolidColorBrush x:Key="ComboBoxForegroundPressed" Color="{StaticResource TextFillColorPrimary}" />
   <SolidColorBrush x:Key="ComboBoxForegroundDisabled" Color="{StaticResource TextFillColorDisabled}" />
-  <!--<SolidColorBrush x:Key="ComboBoxItemBorderBrush" Color="{StaticResource ControlElevationBorderBrush}" />-->
+  <SolidColorBrush x:Key="ComboBoxForegroundFocused" Color="{StaticResource TextFillColorPrimary}" />
+  <SolidColorBrush x:Key="ComboBoxForegroundFocusedPressed" Color="{StaticResource TextFillColorPrimary}" />
+  <LinearGradientBrush x:Key="ComboBoxBorderBrush" MappingMode="Absolute" StartPoint="0,0" EndPoint="0,3">
+    <LinearGradientBrush.RelativeTransform>
+      <ScaleTransform ScaleY="-1" CenterY="0.5" />
+    </LinearGradientBrush.RelativeTransform>
+    <LinearGradientBrush.GradientStops>
+      <GradientStop Offset="0.33" Color="{StaticResource ControlStrokeColorSecondary}" />
+      <GradientStop Offset="1.0" Color="{StaticResource ControlStrokeColorDefault}" />
+    </LinearGradientBrush.GradientStops>
+  </LinearGradientBrush>
+  <LinearGradientBrush x:Key="ComboBoxBorderBrushPointerOver" MappingMode="Absolute" StartPoint="0,0" EndPoint="0,3">
+    <LinearGradientBrush.RelativeTransform>
+      <ScaleTransform ScaleY="-1" CenterY="0.5" />
+    </LinearGradientBrush.RelativeTransform>
+    <LinearGradientBrush.GradientStops>
+      <GradientStop Offset="0.33" Color="{StaticResource ControlStrokeColorSecondary}" />
+      <GradientStop Offset="1.0" Color="{StaticResource ControlStrokeColorDefault}" />
+    </LinearGradientBrush.GradientStops>
+  </LinearGradientBrush>
+  <SolidColorBrush x:Key="ComboBoxBorderBrushPressed" Color="{StaticResource ControlStrokeColorDefault}" />
   <SolidColorBrush x:Key="ComboBoxBorderBrushDisabled" Color="{StaticResource ControlStrokeColorDefault}" />
-  <SolidColorBrush x:Key="ComboBoxBorderBrushFocused" Color="{StaticResource SystemAccentColorDark1}" />
-  <SolidColorBrush x:Key="ComboBoxDropDownGlyphForeground" Color="{StaticResource TextFillColorPrimary}" />
+  <SolidColorBrush x:Key="ComboBoxDropDownGlyphForeground" Color="{StaticResource TextFillColorSecondary}" />
+  <SolidColorBrush x:Key="ComboBoxDropDownGlyphForegroundFocused" Color="{StaticResource TextFillColorSecondary}" />
+  <SolidColorBrush x:Key="ComboBoxDropDownGlyphForegroundFocusedPressed" Color="{StaticResource TextFillColorSecondary}" />
+  <SolidColorBrush x:Key="ComboBoxDropDownGlyphForegroundDisabled" Color="{StaticResource TextFillColorDisabled}" />
+  <SolidColorBrush x:Key="ComboBoxDropDownForeground" Color="{StaticResource TextFillColorPrimary}" />
   <SolidColorBrush x:Key="ComboBoxDropDownBackground" Color="{StaticResource AcrylicBackgroundFillColorDefault}" />
   <SolidColorBrush x:Key="ComboBoxDropDownBorderBrush" Color="{StaticResource SurfaceStrokeColorFlyout}" />
+  <SolidColorBrush x:Key="ComboBoxDropDownBackgroundPointerOver" Color="{StaticResource SubtleFillColorSecondary}" />
+  <SolidColorBrush x:Key="ComboBoxDropDownBackgroundPointerPressed" Color="{StaticResource SubtleFillColorTertiary}" />
+  <SolidColorBrush x:Key="ComboBoxFocusedDropDownBackgroundPointerPressed" Color="{StaticResource ControlAltFillColorQuarternary}" />
+  <SolidColorBrush x:Key="ComboBoxEditableDropDownGlyphForeground" Color="{StaticResource TextFillColorSecondary}" />
+  <!-- Deprecated ComboBox Brushes -->
+  <SolidColorBrush x:Key="ComboBoxBorderBrushFocused" Color="{StaticResource SystemAccentColorDark1}" />
+  <!--<SolidColorBrush x:Key="ComboBoxItemBorderBrush" Color="{StaticResource ControlElevationBorderBrush}" />-->
   <SolidColorBrush x:Key="ComboBoxItemPillFillBrush" Color="{StaticResource SystemAccentColorDark1}" />
   <SolidColorBrush x:Key="ComboBoxItemBackgroundSelected" Color="{StaticResource SubtleFillColorSecondary}" />
   <SolidColorBrush x:Key="ComboBoxItemForeground" Color="{StaticResource TextFillColorPrimary}" />
@@ -1408,49 +1439,78 @@
   <DataTemplate DataType="{x:Type CollectionViewGroup}">
     <ContentPresenter Content="{Binding Path=Name}" ContentStringFormat="{TemplateBinding ContentStringFormat}" />
   </DataTemplate>
-  <Thickness x:Key="ComboBoxPadding">10,8,10,8</Thickness>
-  <Thickness x:Key="ComboBoxBorderThemeThickness">1,1,1,1</Thickness>
+  <!-- Deprecated .NET 9 Keys -->
   <Thickness x:Key="ComboBoxAccentBorderThemeThickness">0,0,0,2</Thickness>
   <Thickness x:Key="ComboBoxChevronMargin">8,0,10,0</Thickness>
-  <Thickness x:Key="ComboBoxItemMargin">3,2,3,0</Thickness>
-  <Thickness x:Key="ComboBoxItemContentMargin">10,8,8,8</Thickness>
-  <system:Double x:Key="ComboBoxChevronSize">11.0</system:Double>
+  <!-- Redefined in .NET 10 -->
+  <!-- <Thickness x:Key="ComboBoxPadding">10,8,10,8</Thickness>
+            <system:Double x:Key="ComboBoxChevronSize">11</system:Double> -->
+  <Thickness x:Key="ComboBoxPadding">12,5,0,7</Thickness>
+  <Thickness x:Key="ComboBoxEditableTextPadding">11,5,38,6</Thickness>
+  <Thickness x:Key="ComboBoxBorderThemeThickness">1,1,1,1</Thickness>
+  <system:Double x:Key="ComboBoxChevronSize">10</system:Double>
   <system:Double x:Key="ComboBoxPopupMinHeight">32.0</system:Double>
   <system:String x:Key="ComboBoxChevronDownGlyph"></system:String>
+  <CornerRadius x:Key="ComboBoxDropDownButtonBackgroundCornerRadius">4</CornerRadius>
+  <Thickness x:Key="ComboBoxItemMargin">3,2,3,0</Thickness>
+  <Thickness x:Key="ComboBoxItemContentMargin">10,8,8,8</Thickness>
   <Style x:Key="DefaultComboBoxTextBoxStyle" TargetType="{x:Type TextBox}">
-    <!--  Focus by parent element  -->
     <Setter Property="FocusVisualStyle" Value="{x:Null}" />
-    <!--  Focus by parent element  -->
-    <!--  Universal WPF UI ContextMenu  -->
     <Setter Property="ContextMenu" Value="{DynamicResource DefaultControlContextMenu}" />
-    <!--  Universal WPF UI ContextMenu  -->
-    <Setter Property="Foreground" Value="{DynamicResource ComboBoxForeground}" />
-    <Setter Property="CaretBrush" Value="{DynamicResource ComboBoxForeground}" />
-    <Setter Property="Background" Value="Transparent" />
-    <Setter Property="Visibility" Value="Hidden" />
+    <Setter Property="Foreground" Value="{DynamicResource TextControlForeground}" />
+    <Setter Property="CaretBrush" Value="{DynamicResource TextControlForeground}" />
+    <Setter Property="BorderBrush" Value="{DynamicResource TextControlElevationBorderBrush}" />
+    <Setter Property="BorderThickness" Value="{StaticResource TextControlBorderThemeThickness}" />
+    <Setter Property="ScrollViewer.HorizontalScrollBarVisibility" Value="Hidden" />
+    <Setter Property="ScrollViewer.VerticalScrollBarVisibility" Value="Hidden" />
+    <Setter Property="HorizontalContentAlignment" Value="Left" />
+    <Setter Property="VerticalContentAlignment" Value="Top" />
     <Setter Property="Cursor" Value="IBeam" />
-    <Setter Property="Margin" Value="0" />
-    <Setter Property="Padding" Value="0" />
-    <Setter Property="SnapsToDevicePixels" Value="True" />
+    <Setter Property="MinHeight" Value="{DynamicResource TextBoxThemeMinHeight}" />
+    <Setter Property="MinWidth" Value="{DynamicResource TextControlThemeMinWidth}" />
+    <Setter Property="Padding" Value="{DynamicResource TextControlThemePadding}" />
+    <Setter Property="Border.CornerRadius" Value="{DynamicResource ControlCornerRadius}" />
+    <Setter Property="AllowDrop" Value="True" />
+    <Setter Property="ScrollViewer.PanningMode" Value="VerticalFirst" />
+    <Setter Property="Stylus.IsFlicksEnabled" Value="False" />
     <Setter Property="OverridesDefaultStyle" Value="True" />
+    <Setter Property="SelectionBrush" Value="{DynamicResource TextControlSelectionHighlightColor}" />
     <Setter Property="Template">
       <Setter.Value>
-        <ControlTemplate TargetType="{x:Type TextBox}">
-          <Decorator x:Name="PART_ContentHost" Margin="{TemplateBinding Padding}" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" TextElement.Foreground="{TemplateBinding Foreground}" />
+        <ControlTemplate TargetType="{x:Type TextBoxBase}">
+          <Grid>
+            <Border x:Name="ContentBorder" MinWidth="{TemplateBinding MinWidth}" MinHeight="{TemplateBinding MinHeight}" Background="{TemplateBinding Background}" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" CornerRadius="{TemplateBinding Border.CornerRadius}" />
+            <ScrollViewer x:Name="PART_ContentHost" Margin="{TemplateBinding BorderThickness}" CanContentScroll="{TemplateBinding ScrollViewer.CanContentScroll}" HorizontalScrollBarVisibility="{TemplateBinding ScrollViewer.HorizontalScrollBarVisibility}" IsDeferredScrollingEnabled="{TemplateBinding ScrollViewer.IsDeferredScrollingEnabled}" IsTabStop="{TemplateBinding ScrollViewer.IsTabStop}" Padding="{TemplateBinding Padding}" TextElement.Foreground="{TemplateBinding Foreground}" VerticalScrollBarVisibility="{TemplateBinding ScrollViewer.VerticalScrollBarVisibility}" />
+          </Grid>
+          <ControlTemplate.Triggers>
+            <Trigger Property="IsMouseOver" Value="True">
+              <!-- Disabling this trigger as this will be handled by the ComboBox style. -->
+              <!--<Setter TargetName="ContentBorder" Property="Background" Value="{DynamicResource TextControlBackgroundPointerOver}" />-->
+              <Setter TargetName="ContentBorder" Property="BorderBrush" Value="{DynamicResource TextControlBorderBrushPointerOver}" />
+              <Setter TargetName="PART_ContentHost" Property="Foreground" Value="{DynamicResource TextControlForegroundPointerOver}" />
+            </Trigger>
+            <Trigger Property="IsFocused" Value="True">
+              <Setter TargetName="ContentBorder" Property="BorderThickness" Value="{StaticResource TextControlBorderThemeThicknessFocused}" />
+              <Setter TargetName="ContentBorder" Property="Background" Value="{DynamicResource TextControlBackgroundFocused}" />
+              <Setter TargetName="ContentBorder" Property="BorderBrush" Value="{DynamicResource TextControlBorderBrushFocused}" />
+              <Setter TargetName="PART_ContentHost" Property="Foreground" Value="{DynamicResource TextControlForegroundFocused}" />
+            </Trigger>
+            <Trigger Property="IsEnabled" Value="False">
+              <Setter TargetName="ContentBorder" Property="Background" Value="{DynamicResource TextControlBackgroundDisabled}" />
+              <Setter TargetName="ContentBorder" Property="BorderBrush" Value="{DynamicResource TextControlBorderBrushDisabled}" />
+              <Setter TargetName="PART_ContentHost" Property="Foreground" Value="{DynamicResource TextControlForegroundDisabled}" />
+            </Trigger>
+          </ControlTemplate.Triggers>
         </ControlTemplate>
       </Setter.Value>
     </Setter>
   </Style>
   <Style x:Key="DefaultComboBoxToggleButtonStyle" TargetType="{x:Type ToggleButton}">
-    <!--  Focus by parent element  -->
     <Setter Property="FocusVisualStyle" Value="{x:Null}" />
-    <!--  Focus by parent element  -->
     <Setter Property="Foreground" Value="{DynamicResource ComboBoxForeground}" />
     <Setter Property="Background" Value="Transparent" />
     <Setter Property="BorderBrush" Value="Transparent" />
-    <Setter Property="BorderThickness" Value="0" />
-    <Setter Property="Border.CornerRadius" Value="0" />
-    <Setter Property="SnapsToDevicePixels" Value="True" />
+    <Setter Property="Border.CornerRadius" Value="{DynamicResource ControlCornerRadius}" />
     <Setter Property="OverridesDefaultStyle" Value="True" />
     <Setter Property="Template">
       <Setter.Value>
@@ -1500,14 +1560,217 @@
       </Setter.Value>
     </Setter>
   </Style>
+  <ControlTemplate x:Key="DefaultComboBoxTemplate" TargetType="{x:Type ComboBox}">
+    <Grid x:Name="LayoutGrid">
+      <Grid.ColumnDefinitions>
+        <ColumnDefinition Width="*" />
+        <ColumnDefinition Width="38" />
+      </Grid.ColumnDefinitions>
+      <Border x:Name="ContentBorder" Grid.ColumnSpan="2" Background="{TemplateBinding Background}" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" CornerRadius="{TemplateBinding Border.CornerRadius}" />
+      <ContentPresenter Name="PART_ContentPresenter" Content="{TemplateBinding SelectionBoxItem}" ContentTemplate="{TemplateBinding SelectionBoxItemTemplate}" ContentTemplateSelector="{TemplateBinding ItemTemplateSelector}" ContentStringFormat="{TemplateBinding SelectionBoxItemStringFormat}" Margin="{TemplateBinding Padding}" TextElement.Foreground="{TemplateBinding Foreground}" HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" VerticalAlignment="{TemplateBinding VerticalContentAlignment}" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" IsHitTestVisible="False" />
+      <ToggleButton x:Name="ToggleButton" Grid.ColumnSpan="2" Focusable="False" IsChecked="{Binding Path=IsDropDownOpen, Mode=TwoWay, RelativeSource={RelativeSource TemplatedParent}}" Style="{StaticResource DefaultComboBoxToggleButtonStyle}" />
+      <TextBlock x:Name="ChevronIcon" Grid.Column="1" HorizontalAlignment="Center" VerticalAlignment="Center" IsHitTestVisible="False" RenderTransformOrigin="0.5,0.5" FontFamily="{DynamicResource SymbolThemeFontFamily}" FontSize="{StaticResource ComboBoxChevronSize}" Text="{StaticResource ComboBoxChevronDownGlyph}">
+        <TextBlock.RenderTransform>
+          <RotateTransform Angle="0" />
+        </TextBlock.RenderTransform>
+      </TextBlock>
+      <Popup x:Name="PART_Popup" MinWidth="{TemplateBinding ActualWidth}" AllowsTransparency="True" Focusable="False" IsOpen="{TemplateBinding IsDropDownOpen}" Placement="{TemplateBinding Popup.Placement}" PopupAnimation="{TemplateBinding Popup.PopupAnimation}" VerticalOffset="1">
+        <Border x:Name="DropDownBorder" Padding="0,4,0,6" Background="{DynamicResource ComboBoxDropDownBackground}" BorderBrush="{DynamicResource ComboBoxDropDownBorderBrush}" BorderThickness="1.5" CornerRadius="{DynamicResource PopupCornerRadius}" SnapsToDevicePixels="True">
+          <Border.RenderTransform>
+            <TranslateTransform />
+          </Border.RenderTransform>
+          <Grid>
+            <ScrollViewer MaxHeight="{TemplateBinding MaxDropDownHeight}" SnapsToDevicePixels="True" HorizontalScrollBarVisibility="{TemplateBinding ScrollViewer.HorizontalScrollBarVisibility}" VerticalScrollBarVisibility="{TemplateBinding ScrollViewer.VerticalScrollBarVisibility}" TextElement.FontSize="{TemplateBinding FontSize}" TextElement.FontWeight="{TemplateBinding FontWeight}" TextElement.Foreground="{TemplateBinding Foreground}">
+              <StackPanel IsItemsHost="True" KeyboardNavigation.DirectionalNavigation="Contained" />
+            </ScrollViewer>
+          </Grid>
+          <Border.Effect>
+            <DropShadowEffect BlurRadius="20" Direction="270" Opacity="0.25" ShadowDepth="6" />
+          </Border.Effect>
+        </Border>
+      </Popup>
+    </Grid>
+    <ControlTemplate.Triggers>
+      <Trigger Property="IsDropDownOpen" Value="True">
+        <Trigger.EnterActions>
+          <BeginStoryboard>
+            <Storyboard>
+              <DoubleAnimation Storyboard.TargetName="ChevronIcon" Storyboard.TargetProperty="(TextBlock.RenderTransform).(RotateTransform.Angle)" From="0" To="180" Duration="00:00:00.167" />
+              <DoubleAnimation Storyboard.TargetName="DropDownBorder" Storyboard.TargetProperty="(Border.RenderTransform).(TranslateTransform.Y)" From="-90" To="0" Duration="00:00:00.167">
+                <DoubleAnimation.EasingFunction>
+                  <CircleEase EasingMode="EaseOut" />
+                </DoubleAnimation.EasingFunction>
+              </DoubleAnimation>
+            </Storyboard>
+          </BeginStoryboard>
+        </Trigger.EnterActions>
+        <Trigger.ExitActions>
+          <BeginStoryboard>
+            <Storyboard>
+              <DoubleAnimation Storyboard.TargetName="ChevronIcon" Storyboard.TargetProperty="(TextBlock.RenderTransform).(RotateTransform.Angle)" From="180" To="0" Duration="00:00:00.167" />
+            </Storyboard>
+          </BeginStoryboard>
+        </Trigger.ExitActions>
+      </Trigger>
+      <Trigger Property="HasItems" Value="False">
+        <Setter TargetName="DropDownBorder" Property="MinHeight" Value="{StaticResource ComboBoxPopupMinHeight}" />
+      </Trigger>
+      <Trigger SourceName="PART_Popup" Property="Popup.AllowsTransparency" Value="False">
+        <Setter TargetName="DropDownBorder" Property="CornerRadius" Value="0" />
+      </Trigger>
+      <Trigger Property="IsGrouping" Value="True">
+        <Setter Property="ScrollViewer.CanContentScroll" Value="False" />
+      </Trigger>
+      <!--PointerOver state-->
+      <Trigger Property="IsMouseOver" Value="True">
+        <Setter TargetName="ContentBorder" Property="Background" Value="{DynamicResource ComboBoxBackgroundPointerOver}" />
+        <Setter TargetName="ContentBorder" Property="BorderBrush" Value="{DynamicResource ComboBoxBorderBrushPointerOver}" />
+        <Setter TargetName="PART_ContentPresenter" Property="TextElement.Foreground" Value="{DynamicResource ComboBoxForegroundPointerOver}" />
+      </Trigger>
+      <!--Pressed state-->
+      <Trigger SourceName="ToggleButton" Property="IsPressed" Value="True">
+        <Setter TargetName="ContentBorder" Property="Background" Value="{DynamicResource ComboBoxBackgroundPressed}" />
+        <Setter TargetName="ContentBorder" Property="BorderBrush" Value="{DynamicResource ComboBoxBorderBrushPressed}" />
+        <Setter TargetName="PART_ContentPresenter" Property="TextElement.Foreground" Value="{DynamicResource ComboBoxForegroundPressed}" />
+      </Trigger>
+      <!--Focused state-->
+      <Trigger Property="IsFocused" Value="True">
+        <Setter TargetName="PART_ContentPresenter" Property="TextElement.Foreground" Value="{DynamicResource ComboBoxForegroundFocused}" />
+        <Setter TargetName="ChevronIcon" Property="Foreground" Value="{DynamicResource ComboBoxDropDownGlyphForegroundFocused}" />
+      </Trigger>
+      <!--FocusedPressed state-->
+      <MultiTrigger>
+        <MultiTrigger.Conditions>
+          <Condition Property="IsFocused" Value="True" />
+          <Condition SourceName="ToggleButton" Property="IsPressed" Value="True" />
+        </MultiTrigger.Conditions>
+        <Setter TargetName="PART_ContentPresenter" Property="TextElement.Foreground" Value="{DynamicResource ComboBoxForegroundFocusedPressed}" />
+        <Setter TargetName="ChevronIcon" Property="Foreground" Value="{DynamicResource ComboBoxDropDownGlyphForegroundFocusedPressed}" />
+      </MultiTrigger>
+      <!--Disabled state-->
+      <Trigger Property="IsEnabled" Value="False">
+        <Setter TargetName="ContentBorder" Property="Background" Value="{DynamicResource ComboBoxBackgroundDisabled}" />
+        <Setter TargetName="ContentBorder" Property="BorderBrush" Value="{DynamicResource ComboBoxBorderBrushDisabled}" />
+        <Setter TargetName="PART_ContentPresenter" Property="TextElement.Foreground" Value="{DynamicResource ComboBoxForegroundDisabled}" />
+        <Setter TargetName="ChevronIcon" Property="Foreground" Value="{DynamicResource ComboBoxDropDownGlyphForegroundDisabled}" />
+      </Trigger>
+    </ControlTemplate.Triggers>
+  </ControlTemplate>
+  <ControlTemplate x:Key="EditableComboBoxTemplate" TargetType="{x:Type ComboBox}">
+    <Grid x:Name="LayoutGrid">
+      <Grid.ColumnDefinitions>
+        <ColumnDefinition Width="*" />
+        <ColumnDefinition Width="38" />
+      </Grid.ColumnDefinitions>
+      <Border x:Name="ContentBorder" Grid.ColumnSpan="2" Background="{TemplateBinding Background}" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" CornerRadius="{TemplateBinding Border.CornerRadius}" />
+      <TextBox x:Name="PART_EditableTextBox" Grid.ColumnSpan="2" Padding="11,5,38,6" Foreground="{TemplateBinding Foreground}" FontSize="{TemplateBinding FontSize}" IsReadOnly="{TemplateBinding IsReadOnly}" Style="{StaticResource DefaultComboBoxTextBoxStyle}" AutomationProperties.Name="{TemplateBinding AutomationProperties.Name}" />
+      <Border x:Name="DropDownOverlay" Grid.Column="1" Margin="4" Width="30" Background="Transparent" CornerRadius="{StaticResource ComboBoxDropDownButtonBackgroundCornerRadius}" />
+      <ToggleButton x:Name="ToggleButton" Grid.Column="1" Margin="4" Focusable="False" IsChecked="{Binding Path=IsDropDownOpen, Mode=TwoWay, RelativeSource={RelativeSource TemplatedParent}}" Style="{StaticResource DefaultComboBoxToggleButtonStyle}" />
+      <TextBlock x:Name="ChevronIcon" Grid.Column="1" HorizontalAlignment="Center" VerticalAlignment="Center" IsHitTestVisible="False" RenderTransformOrigin="0.5,0.5" FontFamily="{DynamicResource SymbolThemeFontFamily}" FontSize="{StaticResource ComboBoxChevronSize}" Text="{StaticResource ComboBoxChevronDownGlyph}">
+        <TextBlock.RenderTransform>
+          <RotateTransform Angle="0" />
+        </TextBlock.RenderTransform>
+      </TextBlock>
+      <Popup x:Name="PART_Popup" Focusable="False" AllowsTransparency="True" MinWidth="{TemplateBinding ActualWidth}" IsOpen="{TemplateBinding IsDropDownOpen}" Placement="{TemplateBinding Popup.Placement}" PopupAnimation="{TemplateBinding Popup.PopupAnimation}" VerticalOffset="1">
+        <Border x:Name="DropDownBorder" Padding="0,4,0,6" BorderThickness="1.5" Background="{DynamicResource ComboBoxDropDownBackground}" BorderBrush="{DynamicResource ComboBoxDropDownBorderBrush}" CornerRadius="{DynamicResource PopupCornerRadius}" SnapsToDevicePixels="True">
+          <Border.RenderTransform>
+            <TranslateTransform />
+          </Border.RenderTransform>
+          <Grid>
+            <ScrollViewer MaxHeight="{TemplateBinding MaxDropDownHeight}" SnapsToDevicePixels="True" HorizontalScrollBarVisibility="{TemplateBinding ScrollViewer.HorizontalScrollBarVisibility}" VerticalScrollBarVisibility="{TemplateBinding ScrollViewer.VerticalScrollBarVisibility}" TextElement.FontSize="{TemplateBinding FontSize}" TextElement.FontWeight="{TemplateBinding FontWeight}" TextElement.Foreground="{TemplateBinding Foreground}">
+              <StackPanel IsItemsHost="True" KeyboardNavigation.DirectionalNavigation="Contained" />
+            </ScrollViewer>
+          </Grid>
+          <Border.Effect>
+            <DropShadowEffect BlurRadius="20" Direction="270" Opacity="0.25" ShadowDepth="6" />
+          </Border.Effect>
+        </Border>
+      </Popup>
+    </Grid>
+    <ControlTemplate.Triggers>
+      <Trigger Property="IsDropDownOpen" Value="True">
+        <Trigger.EnterActions>
+          <BeginStoryboard>
+            <Storyboard>
+              <DoubleAnimation Storyboard.TargetName="ChevronIcon" Storyboard.TargetProperty="(TextBlock.RenderTransform).(RotateTransform.Angle)" From="0" To="180" Duration="00:00:00.167" />
+              <DoubleAnimation Storyboard.TargetName="DropDownBorder" Storyboard.TargetProperty="(Border.RenderTransform).(TranslateTransform.Y)" From="-90" To="0" Duration="00:00:00.167">
+                <DoubleAnimation.EasingFunction>
+                  <CircleEase EasingMode="EaseOut" />
+                </DoubleAnimation.EasingFunction>
+              </DoubleAnimation>
+            </Storyboard>
+          </BeginStoryboard>
+        </Trigger.EnterActions>
+        <Trigger.ExitActions>
+          <BeginStoryboard>
+            <Storyboard>
+              <DoubleAnimation Storyboard.TargetName="ChevronIcon" Storyboard.TargetProperty="(TextBlock.RenderTransform).(RotateTransform.Angle)" From="180" To="0" Duration="00:00:00.167" />
+            </Storyboard>
+          </BeginStoryboard>
+        </Trigger.ExitActions>
+      </Trigger>
+      <Trigger Property="HasItems" Value="False">
+        <Setter TargetName="DropDownBorder" Property="MinHeight" Value="{StaticResource ComboBoxPopupMinHeight}" />
+      </Trigger>
+      <Trigger SourceName="PART_Popup" Property="Popup.AllowsTransparency" Value="False">
+        <Setter TargetName="DropDownBorder" Property="CornerRadius" Value="0" />
+      </Trigger>
+      <Trigger Property="IsGrouping" Value="True">
+        <Setter Property="ScrollViewer.CanContentScroll" Value="False" />
+      </Trigger>
+      <!-- PointerOver state-->
+      <Trigger Property="IsMouseOver" Value="True">
+        <Setter TargetName="ContentBorder" Property="Background" Value="{DynamicResource ComboBoxBackgroundPointerOver}" />
+        <Setter TargetName="ContentBorder" Property="BorderBrush" Value="{DynamicResource ComboBoxBorderBrushPointerOver}" />
+        <Setter TargetName="PART_EditableTextBox" Property="TextElement.Foreground" Value="{DynamicResource ComboBoxForegroundPointerOver}" />
+      </Trigger>
+      <!-- Focused / TextBoxFocused -->
+      <Trigger Property="IsFocused" Value="True">
+        <Setter TargetName="PART_EditableTextBox" Property="TextElement.Foreground" Value="{DynamicResource ComboBoxForegroundFocused}" />
+        <Setter TargetName="ChevronIcon" Property="Foreground" Value="{DynamicResource ComboBoxEditableDropDownGlyphForeground}" />
+      </Trigger>
+      <!--TextBoxOverlayPointerOver state-->
+      <Trigger SourceName="ToggleButton" Property="IsMouseOver" Value="True">
+        <Setter TargetName="DropDownOverlay" Property="Background" Value="{DynamicResource ComboBoxDropDownBackgroundPointerOver}" />
+      </Trigger>
+      <!--TextBoxOverlayPressed-->
+      <Trigger SourceName="ToggleButton" Property="IsPressed" Value="True">
+        <Setter TargetName="DropDownOverlay" Property="Background" Value="{DynamicResource ComboBoxDropDownBackgroundPointerPressed}" />
+      </Trigger>
+      <!--TextBoxFocusedOverlayPointerOver state-->
+      <MultiTrigger>
+        <MultiTrigger.Conditions>
+          <Condition Property="IsFocused" Value="True" />
+          <Condition SourceName="ToggleButton" Property="IsMouseOver" Value="True" />
+        </MultiTrigger.Conditions>
+        <Setter TargetName="DropDownOverlay" Property="Background" Value="{DynamicResource ComboBoxDropDownBackgroundPointerOver}" />
+        <Setter TargetName="ChevronIcon" Property="Foreground" Value="{DynamicResource ComboBoxEditableDropDownGlyphForeground}" />
+      </MultiTrigger>
+      <!-- FocusedPressed state / TextBoxFocusedOverlayPressed state -->
+      <MultiTrigger>
+        <MultiTrigger.Conditions>
+          <Condition Property="IsFocused" Value="True" />
+          <Condition SourceName="ToggleButton" Property="IsPressed" Value="True" />
+        </MultiTrigger.Conditions>
+        <Setter TargetName="ChevronIcon" Property="Foreground" Value="{DynamicResource ComboBoxEditableDropDownGlyphForeground}" />
+        <Setter TargetName="PART_EditableTextBox" Property="TextElement.Foreground" Value="{DynamicResource ComboBoxForegroundFocusedPressed}" />
+        <Setter TargetName="DropDownOverlay" Property="Background" Value="{DynamicResource ComboBoxFocusedDropDownBackgroundPointerPressed}" />
+      </MultiTrigger>
+      <!--Disabled state-->
+      <Trigger Property="IsEnabled" Value="False">
+        <Setter TargetName="ContentBorder" Property="Background" Value="{DynamicResource ComboBoxBackgroundDisabled}" />
+        <Setter TargetName="ContentBorder" Property="BorderBrush" Value="{DynamicResource ComboBoxBorderBrushDisabled}" />
+        <Setter TargetName="PART_EditableTextBox" Property="TextElement.Foreground" Value="{DynamicResource ComboBoxForegroundDisabled}" />
+        <Setter TargetName="ChevronIcon" Property="Foreground" Value="{DynamicResource ComboBoxDropDownGlyphForegroundDisabled}" />
+      </Trigger>
+    </ControlTemplate.Triggers>
+  </ControlTemplate>
   <Style x:Key="DefaultComboBoxStyle" TargetType="{x:Type ComboBox}">
-    <!--  Universal WPF UI focus  -->
     <Setter Property="FocusVisualStyle" Value="{DynamicResource DefaultControlFocusVisualStyle}" />
-    <!--  Universal WPF UI ContextMenu  -->
     <Setter Property="ContextMenu" Value="{DynamicResource DefaultControlContextMenu}" />
     <Setter Property="Foreground" Value="{DynamicResource ComboBoxForeground}" />
     <Setter Property="Background" Value="{DynamicResource ComboBoxBackground}" />
-    <Setter Property="BorderBrush" Value="{DynamicResource ControlElevationBorderBrush}" />
+    <Setter Property="BorderBrush" Value="{DynamicResource ComboBoxBorderBrush}" />
     <Setter Property="BorderThickness" Value="{StaticResource ComboBoxBorderThemeThickness}" />
     <Setter Property="ScrollViewer.CanContentScroll" Value="False" />
     <Setter Property="ScrollViewer.HorizontalScrollBarVisibility" Value="Auto" />
@@ -1522,125 +1785,15 @@
     <Setter Property="Padding" Value="{DynamicResource ComboBoxPadding}" />
     <Setter Property="Border.CornerRadius" Value="{DynamicResource ControlCornerRadius}" />
     <Setter Property="Popup.PopupAnimation" Value="None" />
-    <!--  WPF doesn't like centering, the animation is ugly and the mouse button sometimes clicks right away.  -->
     <Setter Property="Popup.Placement" Value="Bottom" />
     <Setter Property="SnapsToDevicePixels" Value="True" />
     <Setter Property="OverridesDefaultStyle" Value="True" />
-    <Setter Property="Template">
-      <Setter.Value>
-        <ControlTemplate TargetType="{x:Type ComboBox}">
-          <Grid>
-            <Border x:Name="ContentBorder" Grid.Row="0" MinWidth="{TemplateBinding MinWidth}" MinHeight="{TemplateBinding MinHeight}" Padding="0" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" Background="{TemplateBinding Background}" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" CornerRadius="{TemplateBinding Border.CornerRadius}">
-              <Grid HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" VerticalAlignment="{TemplateBinding VerticalContentAlignment}">
-                <!--
-                                    Funky grid - because:
-                                    Chevron is over Presenter, ToggleButton is over Chevron, TextBox is over ToggleButton.
-                                    But, TextBox is not over Chevron, so ToggleButton still works.
-                                -->
-                <Grid>
-                  <Grid.ColumnDefinitions>
-                    <ColumnDefinition Width="*" />
-                    <ColumnDefinition Width="Auto" />
-                  </Grid.ColumnDefinitions>
-                  <Grid Grid.Column="0" Margin="{TemplateBinding Padding}">
-                    <ContentPresenter Name="PART_ContentPresenter" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" Content="{TemplateBinding SelectionBoxItem}" ContentTemplate="{TemplateBinding SelectionBoxItemTemplate}" ContentTemplateSelector="{TemplateBinding ItemTemplateSelector}" ContentStringFormat="{TemplateBinding SelectionBoxItemStringFormat}" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" IsHitTestVisible="False" TextElement.Foreground="{TemplateBinding Foreground}" />
-                  </Grid>
-                  <Grid Grid.Column="1" Margin="{StaticResource ComboBoxChevronMargin}">
-                    <TextBlock x:Name="ChevronIcon" Margin="0" VerticalAlignment="Center" FontSize="{StaticResource ComboBoxChevronSize}" Foreground="{DynamicResource ComboBoxDropDownGlyphForeground}" RenderTransformOrigin="0.5, 0.5" FontFamily="{DynamicResource SymbolThemeFontFamily}" Text="{StaticResource ComboBoxChevronDownGlyph}">
-                      <TextBlock.RenderTransform>
-                        <RotateTransform Angle="0" />
-                      </TextBlock.RenderTransform>
-                    </TextBlock>
-                  </Grid>
-                  <Grid Grid.Column="0" Grid.ColumnSpan="2" Margin="0">
-                    <ToggleButton Name="ToggleButton" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" ClickMode="Press" Focusable="False" Foreground="{TemplateBinding Foreground}" IsChecked="{Binding Path=IsDropDownOpen, Mode=TwoWay, RelativeSource={RelativeSource TemplatedParent}}" Style="{StaticResource DefaultComboBoxToggleButtonStyle}" />
-                  </Grid>
-                  <Grid Grid.Column="0" Margin="{TemplateBinding Padding}">
-                    <TextBox x:Name="PART_EditableTextBox" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" FontSize="{TemplateBinding FontSize}" Foreground="{TemplateBinding Foreground}" IsReadOnly="{TemplateBinding IsReadOnly}" Style="{StaticResource DefaultComboBoxTextBoxStyle}" AutomationProperties.Name="{TemplateBinding AutomationProperties.Name}" />
-                  </Grid>
-                </Grid>
-                <Popup x:Name="PART_Popup" MinWidth="{TemplateBinding ActualWidth}" VerticalAlignment="Center" AllowsTransparency="True" Focusable="False" IsOpen="{TemplateBinding IsDropDownOpen}" Placement="{TemplateBinding Popup.Placement}" PopupAnimation="{TemplateBinding Popup.PopupAnimation}" VerticalOffset="1">
-                  <Border x:Name="DropDownBorder" Padding="0,4,0,6" Background="{DynamicResource ComboBoxDropDownBackground}" BorderBrush="{DynamicResource ComboBoxDropDownBorderBrush}" BorderThickness="1.5" CornerRadius="{DynamicResource PopupCornerRadius}" SnapsToDevicePixels="True">
-                    <!--Will revist this code while doing performance evaluation for dynamic resources.-->
-                    <Border.RenderTransform>
-                      <TranslateTransform />
-                    </Border.RenderTransform>
-                    <Grid>
-                      <ScrollViewer MaxHeight="{TemplateBinding MaxDropDownHeight}" Margin="0" HorizontalScrollBarVisibility="{TemplateBinding ScrollViewer.HorizontalScrollBarVisibility}" SnapsToDevicePixels="True" TextElement.FontSize="{TemplateBinding FontSize}" TextElement.FontWeight="{TemplateBinding FontWeight}" TextElement.Foreground="{TemplateBinding Foreground}" VerticalScrollBarVisibility="{TemplateBinding ScrollViewer.VerticalScrollBarVisibility}">
-                        <ItemsPresenter KeyboardNavigation.DirectionalNavigation="Contained" TextElement.FontSize="{TemplateBinding FontSize}" />
-                      </ScrollViewer>
-                    </Grid>
-                    <Border.Effect>
-                      <DropShadowEffect BlurRadius="20" Direction="270" Opacity="0.25" ShadowDepth="6" />
-                    </Border.Effect>
-                  </Border>
-                </Popup>
-              </Grid>
-            </Border>
-            <Border x:Name="AccentBorder" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" BorderBrush="{DynamicResource ComboBoxBorderBrushFocused}" BorderThickness="{StaticResource ComboBoxAccentBorderThemeThickness}" CornerRadius="{TemplateBinding Border.CornerRadius}" Visibility="Collapsed" />
-          </Grid>
-          <ControlTemplate.Triggers>
-            <Trigger Property="IsDropDownOpen" Value="True">
-              <Trigger.EnterActions>
-                <BeginStoryboard>
-                  <Storyboard>
-                    <DoubleAnimation Storyboard.TargetName="ChevronIcon" Storyboard.TargetProperty="(TextBlock.RenderTransform).(RotateTransform.Angle)" From="0" To="180" Duration="00:00:00.167" />
-                    <DoubleAnimation Storyboard.TargetName="DropDownBorder" Storyboard.TargetProperty="(Border.RenderTransform).(TranslateTransform.Y)" From="-90" To="0" Duration="00:00:00.167">
-                      <DoubleAnimation.EasingFunction>
-                        <CircleEase EasingMode="EaseOut" />
-                      </DoubleAnimation.EasingFunction>
-                    </DoubleAnimation>
-                  </Storyboard>
-                </BeginStoryboard>
-              </Trigger.EnterActions>
-              <Trigger.ExitActions>
-                <BeginStoryboard>
-                  <Storyboard>
-                    <DoubleAnimation Storyboard.TargetName="ChevronIcon" Storyboard.TargetProperty="(TextBlock.RenderTransform).(RotateTransform.Angle)" From="180" To="0" Duration="00:00:00.167" />
-                  </Storyboard>
-                </BeginStoryboard>
-              </Trigger.ExitActions>
-            </Trigger>
-            <Trigger Property="HasItems" Value="False">
-              <Setter TargetName="DropDownBorder" Property="MinHeight" Value="{StaticResource ComboBoxPopupMinHeight}" />
-            </Trigger>
-            <Trigger SourceName="PART_Popup" Property="Popup.AllowsTransparency" Value="False">
-              <Setter TargetName="DropDownBorder" Property="CornerRadius" Value="0" />
-            </Trigger>
-            <Trigger Property="IsGrouping" Value="True">
-              <Setter Property="ScrollViewer.CanContentScroll" Value="False" />
-            </Trigger>
-            <Trigger Property="IsEditable" Value="True">
-              <Setter Property="IsTabStop" Value="False" />
-              <Setter TargetName="PART_EditableTextBox" Property="Visibility" Value="Visible" />
-              <Setter TargetName="PART_ContentPresenter" Property="Visibility" Value="Hidden" />
-            </Trigger>
-            <MultiTrigger>
-              <MultiTrigger.Conditions>
-                <Condition Property="IsEnabled" Value="True" />
-                <Condition Property="IsKeyboardFocusWithin" Value="True" />
-                <Condition Property="IsEditable" Value="True" />
-              </MultiTrigger.Conditions>
-              <Setter TargetName="ContentBorder" Property="Background" Value="{DynamicResource ComboBoxBackgroundFocused}" />
-              <Setter TargetName="AccentBorder" Property="Visibility" Value="Visible" />
-            </MultiTrigger>
-            <MultiTrigger>
-              <MultiTrigger.Conditions>
-                <Condition Property="IsEnabled" Value="True" />
-                <Condition Property="IsMouseOver" Value="True" />
-                <Condition Property="IsKeyboardFocusWithin" Value="False" />
-              </MultiTrigger.Conditions>
-              <Setter TargetName="ContentBorder" Property="Background" Value="{DynamicResource ComboBoxBackgroundPointerOver}" />
-            </MultiTrigger>
-            <Trigger Property="IsEnabled" Value="False">
-              <Setter TargetName="ContentBorder" Property="Background" Value="{DynamicResource ComboBoxBackgroundDisabled}" />
-              <Setter TargetName="ContentBorder" Property="BorderBrush" Value="{DynamicResource ComboBoxBorderBrushDisabled}" />
-              <Setter Property="Foreground" Value="{DynamicResource ComboBoxForegroundDisabled}" />
-            </Trigger>
-          </ControlTemplate.Triggers>
-        </ControlTemplate>
-      </Setter.Value>
-    </Setter>
+    <Setter Property="Template" Value="{StaticResource DefaultComboBoxTemplate}" />
+    <Style.Triggers>
+      <Trigger Property="IsEditable" Value="True">
+        <Setter Property="Template" Value="{StaticResource EditableComboBoxTemplate}" />
+      </Trigger>
+    </Style.Triggers>
   </Style>
   <Style BasedOn="{StaticResource DefaultComboBoxItemStyle}" TargetType="{x:Type ComboBoxItem}" />
   <Style BasedOn="{StaticResource DefaultComboBoxStyle}" TargetType="{x:Type ComboBox}" />

From 244f6e5c2a9b8ef1563c43b7e6bcb905e3378ac7 Mon Sep 17 00:00:00 2001
From: dipeshmsft <dipeshkumar@microsoft.com>
Date: Wed, 7 May 2025 18:00:02 +0530
Subject: [PATCH 2/6] Addressed PR Review comments

---
 .../PresentationFramework.Fluent/Resources/Variables.xaml      | 1 -
 .../Themes/PresentationFramework.Fluent/Styles/ComboBox.xaml   | 2 +-
 .../PresentationFramework.Fluent/Themes/Fluent.Dark.xaml       | 3 +--
 .../Themes/PresentationFramework.Fluent/Themes/Fluent.HC.xaml  | 3 +--
 .../PresentationFramework.Fluent/Themes/Fluent.Light.xaml      | 3 +--
 5 files changed, 4 insertions(+), 8 deletions(-)

diff --git a/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Resources/Variables.xaml b/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Resources/Variables.xaml
index c9172d5c427..eaf7682d25d 100644
--- a/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Resources/Variables.xaml
+++ b/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Resources/Variables.xaml
@@ -46,7 +46,6 @@
     <Thickness x:Key="TextControlErrorBorderPadding">1</Thickness>
 
     <system:Double x:Key="ComboBoxMinHeight">24</system:Double>
-    <!-- <Thickness x:Key="ComboBoxPadding">12,1,0,3</Thickness> -->
     <system:Double x:Key="NavigationViewItemOnLeftMinHeight">32</system:Double>
 
 </ResourceDictionary>
diff --git a/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Styles/ComboBox.xaml b/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Styles/ComboBox.xaml
index 7c324846e8c..36bcabb9ee4 100644
--- a/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Styles/ComboBox.xaml
+++ b/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Styles/ComboBox.xaml
@@ -79,7 +79,7 @@
                     </Grid>
                     <ControlTemplate.Triggers>
                         <Trigger Property="IsMouseOver" Value="True">
-                            <!-- Disabling this trigger as this will be handled by the ComboBox style. -->
+                            <!-- Disabling this setter as this will be handled by the ComboBox style. -->
                             <!--<Setter TargetName="ContentBorder" Property="Background" Value="{DynamicResource TextControlBackgroundPointerOver}" />-->
                             <Setter TargetName="ContentBorder" Property="BorderBrush" Value="{DynamicResource TextControlBorderBrushPointerOver}" />
                             <Setter TargetName="PART_ContentHost" Property="Foreground" Value="{DynamicResource TextControlForegroundPointerOver}" />
diff --git a/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.Dark.xaml b/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.Dark.xaml
index 28c89caf450..dd1fdc59902 100644
--- a/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.Dark.xaml
+++ b/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.Dark.xaml
@@ -79,7 +79,6 @@
   <Thickness x:Key="DatePickerHostMonthPadding">9,0,0,1</Thickness>
   <!-- <Thickness x:Key="ComboBoxEditableTextPadding">10,0,30,0</Thickness> -->
   <system:Double x:Key="ComboBoxMinHeight">24</system:Double>
-  <!-- <Thickness x:Key="ComboBoxPadding">12,1,0,3</Thickness> -->
   <system:Double x:Key="NavigationViewItemOnLeftMinHeight">32</system:Double>
   <!--
         Microsoft UI XAML
@@ -1469,7 +1468,7 @@
           </Grid>
           <ControlTemplate.Triggers>
             <Trigger Property="IsMouseOver" Value="True">
-              <!-- Disabling this trigger as this will be handled by the ComboBox style. -->
+              <!-- Disabling this setter as this will be handled by the ComboBox style. -->
               <!--<Setter TargetName="ContentBorder" Property="Background" Value="{DynamicResource TextControlBackgroundPointerOver}" />-->
               <Setter TargetName="ContentBorder" Property="BorderBrush" Value="{DynamicResource TextControlBorderBrushPointerOver}" />
               <Setter TargetName="PART_ContentHost" Property="Foreground" Value="{DynamicResource TextControlForegroundPointerOver}" />
diff --git a/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.HC.xaml b/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.HC.xaml
index d97649a0b0c..e9f87f459c2 100644
--- a/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.HC.xaml
+++ b/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.HC.xaml
@@ -79,7 +79,6 @@
   <Thickness x:Key="DatePickerHostMonthPadding">9,0,0,1</Thickness>
   <!-- <Thickness x:Key="ComboBoxEditableTextPadding">10,0,30,0</Thickness> -->
   <system:Double x:Key="ComboBoxMinHeight">24</system:Double>
-  <!-- <Thickness x:Key="ComboBoxPadding">12,1,0,3</Thickness> -->
   <system:Double x:Key="NavigationViewItemOnLeftMinHeight">32</system:Double>
   <!--
         Microsoft UI XAML
@@ -1372,7 +1371,7 @@
           </Grid>
           <ControlTemplate.Triggers>
             <Trigger Property="IsMouseOver" Value="True">
-              <!-- Disabling this trigger as this will be handled by the ComboBox style. -->
+              <!-- Disabling this setter as this will be handled by the ComboBox style. -->
               <!--<Setter TargetName="ContentBorder" Property="Background" Value="{DynamicResource TextControlBackgroundPointerOver}" />-->
               <Setter TargetName="ContentBorder" Property="BorderBrush" Value="{DynamicResource TextControlBorderBrushPointerOver}" />
               <Setter TargetName="PART_ContentHost" Property="Foreground" Value="{DynamicResource TextControlForegroundPointerOver}" />
diff --git a/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.Light.xaml b/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.Light.xaml
index d3ff3fe18ee..00627c96b35 100644
--- a/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.Light.xaml
+++ b/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.Light.xaml
@@ -79,7 +79,6 @@
   <Thickness x:Key="DatePickerHostMonthPadding">9,0,0,1</Thickness>
   <!-- <Thickness x:Key="ComboBoxEditableTextPadding">10,0,30,0</Thickness> -->
   <system:Double x:Key="ComboBoxMinHeight">24</system:Double>
-  <!-- <Thickness x:Key="ComboBoxPadding">12,1,0,3</Thickness> -->
   <system:Double x:Key="NavigationViewItemOnLeftMinHeight">32</system:Double>
   <!--
         Microsoft UI XAML
@@ -1484,7 +1483,7 @@
           </Grid>
           <ControlTemplate.Triggers>
             <Trigger Property="IsMouseOver" Value="True">
-              <!-- Disabling this trigger as this will be handled by the ComboBox style. -->
+              <!-- Disabling this setter as this will be handled by the ComboBox style. -->
               <!--<Setter TargetName="ContentBorder" Property="Background" Value="{DynamicResource TextControlBackgroundPointerOver}" />-->
               <Setter TargetName="ContentBorder" Property="BorderBrush" Value="{DynamicResource TextControlBorderBrushPointerOver}" />
               <Setter TargetName="PART_ContentHost" Property="Foreground" Value="{DynamicResource TextControlForegroundPointerOver}" />

From 1d91e22590fb0b3cb5200b96d604365a63ba5c4c Mon Sep 17 00:00:00 2001
From: dipeshmsft <dipeshkumar@microsoft.com>
Date: Mon, 12 May 2025 16:22:33 +0530
Subject: [PATCH 3/6] Addressed BorderThickness issue

---
 .../Themes/PresentationFramework.Fluent/Styles/ComboBox.xaml  | 4 ++--
 .../PresentationFramework.Fluent/Themes/Fluent.Dark.xaml      | 4 ++--
 .../Themes/PresentationFramework.Fluent/Themes/Fluent.HC.xaml | 4 ++--
 .../PresentationFramework.Fluent/Themes/Fluent.Light.xaml     | 4 ++--
 4 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Styles/ComboBox.xaml b/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Styles/ComboBox.xaml
index 36bcabb9ee4..b16f5ec5aaa 100644
--- a/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Styles/ComboBox.xaml
+++ b/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Styles/ComboBox.xaml
@@ -38,7 +38,7 @@
         <Setter Property="Foreground" Value="{DynamicResource TextControlForeground}" />
         <Setter Property="CaretBrush" Value="{DynamicResource TextControlForeground}" />
         <Setter Property="BorderBrush" Value="{DynamicResource TextControlElevationBorderBrush}" />
-        <Setter Property="BorderThickness" Value="{StaticResource TextControlBorderThemeThickness}" />
+        <Setter Property="BorderThickness" Value="{DynamicResource TextControlBorderThemeThickness}" />
         <Setter Property="ScrollViewer.HorizontalScrollBarVisibility" Value="Hidden" />
         <Setter Property="ScrollViewer.VerticalScrollBarVisibility" Value="Hidden" />
         <Setter Property="HorizontalContentAlignment" Value="Left" />
@@ -85,7 +85,7 @@
                             <Setter TargetName="PART_ContentHost" Property="Foreground" Value="{DynamicResource TextControlForegroundPointerOver}" />
                         </Trigger>
                         <Trigger Property="IsFocused" Value="True">
-                            <Setter TargetName="ContentBorder" Property="BorderThickness" Value="{StaticResource TextControlBorderThemeThicknessFocused}" />
+                            <Setter TargetName="ContentBorder" Property="BorderThickness" Value="{DynamicResource TextControlBorderThemeThicknessFocused}" />
                             <Setter TargetName="ContentBorder" Property="Background" Value="{DynamicResource TextControlBackgroundFocused}" />
                             <Setter TargetName="ContentBorder" Property="BorderBrush" Value="{DynamicResource TextControlBorderBrushFocused}" />
                             <Setter TargetName="PART_ContentHost" Property="Foreground" Value="{DynamicResource TextControlForegroundFocused}" />
diff --git a/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.Dark.xaml b/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.Dark.xaml
index dd1fdc59902..802c7330329 100644
--- a/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.Dark.xaml
+++ b/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.Dark.xaml
@@ -1444,7 +1444,7 @@
     <Setter Property="Foreground" Value="{DynamicResource TextControlForeground}" />
     <Setter Property="CaretBrush" Value="{DynamicResource TextControlForeground}" />
     <Setter Property="BorderBrush" Value="{DynamicResource TextControlElevationBorderBrush}" />
-    <Setter Property="BorderThickness" Value="{StaticResource TextControlBorderThemeThickness}" />
+    <Setter Property="BorderThickness" Value="{DynamicResource TextControlBorderThemeThickness}" />
     <Setter Property="ScrollViewer.HorizontalScrollBarVisibility" Value="Hidden" />
     <Setter Property="ScrollViewer.VerticalScrollBarVisibility" Value="Hidden" />
     <Setter Property="HorizontalContentAlignment" Value="Left" />
@@ -1474,7 +1474,7 @@
               <Setter TargetName="PART_ContentHost" Property="Foreground" Value="{DynamicResource TextControlForegroundPointerOver}" />
             </Trigger>
             <Trigger Property="IsFocused" Value="True">
-              <Setter TargetName="ContentBorder" Property="BorderThickness" Value="{StaticResource TextControlBorderThemeThicknessFocused}" />
+              <Setter TargetName="ContentBorder" Property="BorderThickness" Value="{DynamicResource TextControlBorderThemeThicknessFocused}" />
               <Setter TargetName="ContentBorder" Property="Background" Value="{DynamicResource TextControlBackgroundFocused}" />
               <Setter TargetName="ContentBorder" Property="BorderBrush" Value="{DynamicResource TextControlBorderBrushFocused}" />
               <Setter TargetName="PART_ContentHost" Property="Foreground" Value="{DynamicResource TextControlForegroundFocused}" />
diff --git a/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.HC.xaml b/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.HC.xaml
index e9f87f459c2..06455452d9d 100644
--- a/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.HC.xaml
+++ b/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.HC.xaml
@@ -1347,7 +1347,7 @@
     <Setter Property="Foreground" Value="{DynamicResource TextControlForeground}" />
     <Setter Property="CaretBrush" Value="{DynamicResource TextControlForeground}" />
     <Setter Property="BorderBrush" Value="{DynamicResource TextControlElevationBorderBrush}" />
-    <Setter Property="BorderThickness" Value="{StaticResource TextControlBorderThemeThickness}" />
+    <Setter Property="BorderThickness" Value="{DynamicResource TextControlBorderThemeThickness}" />
     <Setter Property="ScrollViewer.HorizontalScrollBarVisibility" Value="Hidden" />
     <Setter Property="ScrollViewer.VerticalScrollBarVisibility" Value="Hidden" />
     <Setter Property="HorizontalContentAlignment" Value="Left" />
@@ -1377,7 +1377,7 @@
               <Setter TargetName="PART_ContentHost" Property="Foreground" Value="{DynamicResource TextControlForegroundPointerOver}" />
             </Trigger>
             <Trigger Property="IsFocused" Value="True">
-              <Setter TargetName="ContentBorder" Property="BorderThickness" Value="{StaticResource TextControlBorderThemeThicknessFocused}" />
+              <Setter TargetName="ContentBorder" Property="BorderThickness" Value="{DynamicResource TextControlBorderThemeThicknessFocused}" />
               <Setter TargetName="ContentBorder" Property="Background" Value="{DynamicResource TextControlBackgroundFocused}" />
               <Setter TargetName="ContentBorder" Property="BorderBrush" Value="{DynamicResource TextControlBorderBrushFocused}" />
               <Setter TargetName="PART_ContentHost" Property="Foreground" Value="{DynamicResource TextControlForegroundFocused}" />
diff --git a/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.Light.xaml b/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.Light.xaml
index 00627c96b35..6548d321b0e 100644
--- a/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.Light.xaml
+++ b/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.Light.xaml
@@ -1459,7 +1459,7 @@
     <Setter Property="Foreground" Value="{DynamicResource TextControlForeground}" />
     <Setter Property="CaretBrush" Value="{DynamicResource TextControlForeground}" />
     <Setter Property="BorderBrush" Value="{DynamicResource TextControlElevationBorderBrush}" />
-    <Setter Property="BorderThickness" Value="{StaticResource TextControlBorderThemeThickness}" />
+    <Setter Property="BorderThickness" Value="{DynamicResource TextControlBorderThemeThickness}" />
     <Setter Property="ScrollViewer.HorizontalScrollBarVisibility" Value="Hidden" />
     <Setter Property="ScrollViewer.VerticalScrollBarVisibility" Value="Hidden" />
     <Setter Property="HorizontalContentAlignment" Value="Left" />
@@ -1489,7 +1489,7 @@
               <Setter TargetName="PART_ContentHost" Property="Foreground" Value="{DynamicResource TextControlForegroundPointerOver}" />
             </Trigger>
             <Trigger Property="IsFocused" Value="True">
-              <Setter TargetName="ContentBorder" Property="BorderThickness" Value="{StaticResource TextControlBorderThemeThicknessFocused}" />
+              <Setter TargetName="ContentBorder" Property="BorderThickness" Value="{DynamicResource TextControlBorderThemeThicknessFocused}" />
               <Setter TargetName="ContentBorder" Property="Background" Value="{DynamicResource TextControlBackgroundFocused}" />
               <Setter TargetName="ContentBorder" Property="BorderBrush" Value="{DynamicResource TextControlBorderBrushFocused}" />
               <Setter TargetName="PART_ContentHost" Property="Foreground" Value="{DynamicResource TextControlForegroundFocused}" />

From 4a0fc861bfdf307e92aa5d8d91a55d1e43a55356 Mon Sep 17 00:00:00 2001
From: dipeshmsft <dipeshkumar@microsoft.com>
Date: Tue, 3 Jun 2025 15:04:12 +0530
Subject: [PATCH 4/6] Removed extra variables

---
 .../Themes/PresentationFramework.Fluent/Resources/Variables.xaml | 1 -
 .../Themes/PresentationFramework.Fluent/Themes/Fluent.Dark.xaml  | 1 -
 .../Themes/PresentationFramework.Fluent/Themes/Fluent.HC.xaml    | 1 -
 .../Themes/PresentationFramework.Fluent/Themes/Fluent.Light.xaml | 1 -
 4 files changed, 4 deletions(-)

diff --git a/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Resources/Variables.xaml b/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Resources/Variables.xaml
index eaf7682d25d..3f7d0a2003c 100644
--- a/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Resources/Variables.xaml
+++ b/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Resources/Variables.xaml
@@ -3,7 +3,6 @@
     If a copy of the MIT was not distributed with this file, You can obtain one at https://opensource.org/licenses/MIT.
     Copyright (C) Leszek Pomianowski and WPF UI Contributors.
     All Rights Reserved.
-    
     Based on Microsoft XAML for Win UI
     Copyright (c) Microsoft Corporation. All Rights Reserved.
 -->
diff --git a/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.Dark.xaml b/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.Dark.xaml
index 802c7330329..679ac115f59 100644
--- a/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.Dark.xaml
+++ b/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.Dark.xaml
@@ -77,7 +77,6 @@
   <Thickness x:Key="TimePickerHostPadding">0,1,0,2</Thickness>
   <Thickness x:Key="DatePickerHostPadding">0,1,0,2</Thickness>
   <Thickness x:Key="DatePickerHostMonthPadding">9,0,0,1</Thickness>
-  <!-- <Thickness x:Key="ComboBoxEditableTextPadding">10,0,30,0</Thickness> -->
   <system:Double x:Key="ComboBoxMinHeight">24</system:Double>
   <system:Double x:Key="NavigationViewItemOnLeftMinHeight">32</system:Double>
   <!--
diff --git a/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.HC.xaml b/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.HC.xaml
index 06455452d9d..12a8a7e5942 100644
--- a/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.HC.xaml
+++ b/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.HC.xaml
@@ -77,7 +77,6 @@
   <Thickness x:Key="TimePickerHostPadding">0,1,0,2</Thickness>
   <Thickness x:Key="DatePickerHostPadding">0,1,0,2</Thickness>
   <Thickness x:Key="DatePickerHostMonthPadding">9,0,0,1</Thickness>
-  <!-- <Thickness x:Key="ComboBoxEditableTextPadding">10,0,30,0</Thickness> -->
   <system:Double x:Key="ComboBoxMinHeight">24</system:Double>
   <system:Double x:Key="NavigationViewItemOnLeftMinHeight">32</system:Double>
   <!--
diff --git a/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.Light.xaml b/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.Light.xaml
index 6548d321b0e..8ada9ffd885 100644
--- a/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.Light.xaml
+++ b/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.Light.xaml
@@ -77,7 +77,6 @@
   <Thickness x:Key="TimePickerHostPadding">0,1,0,2</Thickness>
   <Thickness x:Key="DatePickerHostPadding">0,1,0,2</Thickness>
   <Thickness x:Key="DatePickerHostMonthPadding">9,0,0,1</Thickness>
-  <!-- <Thickness x:Key="ComboBoxEditableTextPadding">10,0,30,0</Thickness> -->
   <system:Double x:Key="ComboBoxMinHeight">24</system:Double>
   <system:Double x:Key="NavigationViewItemOnLeftMinHeight">32</system:Double>
   <!--

From ed51f1a22050cb9df241d32720b1860f57251e79 Mon Sep 17 00:00:00 2001
From: dipeshmsft <dipeshkumar@microsoft.com>
Date: Tue, 3 Jun 2025 15:23:51 +0530
Subject: [PATCH 5/6] Rebased the branch to use the new theme file genenration

---
 .../Themes/Fluent.Dark.xaml                   |   1 +
 .../Themes/Fluent.HC.xaml                     |   1 +
 .../Themes/Fluent.Light.xaml                  |   1 +
 .../Themes/Fluent.xaml                        | 408 +++++++++++-------
 4 files changed, 267 insertions(+), 144 deletions(-)

diff --git a/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.Dark.xaml b/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.Dark.xaml
index 679ac115f59..a51b384fc8f 100644
--- a/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.Dark.xaml
+++ b/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.Dark.xaml
@@ -77,6 +77,7 @@
   <Thickness x:Key="TimePickerHostPadding">0,1,0,2</Thickness>
   <Thickness x:Key="DatePickerHostPadding">0,1,0,2</Thickness>
   <Thickness x:Key="DatePickerHostMonthPadding">9,0,0,1</Thickness>
+  <Thickness x:Key="TextControlErrorBorderPadding">1</Thickness>
   <system:Double x:Key="ComboBoxMinHeight">24</system:Double>
   <system:Double x:Key="NavigationViewItemOnLeftMinHeight">32</system:Double>
   <!--
diff --git a/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.HC.xaml b/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.HC.xaml
index 12a8a7e5942..2df2fe51146 100644
--- a/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.HC.xaml
+++ b/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.HC.xaml
@@ -77,6 +77,7 @@
   <Thickness x:Key="TimePickerHostPadding">0,1,0,2</Thickness>
   <Thickness x:Key="DatePickerHostPadding">0,1,0,2</Thickness>
   <Thickness x:Key="DatePickerHostMonthPadding">9,0,0,1</Thickness>
+  <Thickness x:Key="TextControlErrorBorderPadding">1</Thickness>
   <system:Double x:Key="ComboBoxMinHeight">24</system:Double>
   <system:Double x:Key="NavigationViewItemOnLeftMinHeight">32</system:Double>
   <!--
diff --git a/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.Light.xaml b/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.Light.xaml
index 8ada9ffd885..0128462f289 100644
--- a/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.Light.xaml
+++ b/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.Light.xaml
@@ -77,6 +77,7 @@
   <Thickness x:Key="TimePickerHostPadding">0,1,0,2</Thickness>
   <Thickness x:Key="DatePickerHostPadding">0,1,0,2</Thickness>
   <Thickness x:Key="DatePickerHostMonthPadding">9,0,0,1</Thickness>
+  <Thickness x:Key="TextControlErrorBorderPadding">1</Thickness>
   <system:Double x:Key="ComboBoxMinHeight">24</system:Double>
   <system:Double x:Key="NavigationViewItemOnLeftMinHeight">32</system:Double>
   <!--
diff --git a/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.xaml b/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.xaml
index 69d0fe6b268..a1906afee7f 100644
--- a/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.xaml
+++ b/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.xaml
@@ -77,10 +77,8 @@
   <Thickness x:Key="TimePickerHostPadding">0,1,0,2</Thickness>
   <Thickness x:Key="DatePickerHostPadding">0,1,0,2</Thickness>
   <Thickness x:Key="DatePickerHostMonthPadding">9,0,0,1</Thickness>
-  <Thickness x:Key="ComboBoxEditableTextPadding">10,0,30,0</Thickness>
   <Thickness x:Key="TextControlErrorBorderPadding">1</Thickness>
   <system:Double x:Key="ComboBoxMinHeight">24</system:Double>
-  <!-- <Thickness x:Key="ComboBoxPadding">12,1,0,3</Thickness> -->
   <system:Double x:Key="NavigationViewItemOnLeftMinHeight">32</system:Double>
   <Thickness x:Key="ButtonPadding">11,5,11,6</Thickness>
   <Thickness x:Key="ButtonBorderThemeThickness">1</Thickness>
@@ -652,49 +650,78 @@
   <DataTemplate DataType="{x:Type CollectionViewGroup}">
     <ContentPresenter Content="{Binding Path=Name}" ContentStringFormat="{TemplateBinding ContentStringFormat}" />
   </DataTemplate>
-  <Thickness x:Key="ComboBoxPadding">10,8,10,8</Thickness>
-  <Thickness x:Key="ComboBoxBorderThemeThickness">1,1,1,1</Thickness>
+  <!-- Deprecated .NET 9 Keys -->
   <Thickness x:Key="ComboBoxAccentBorderThemeThickness">0,0,0,2</Thickness>
   <Thickness x:Key="ComboBoxChevronMargin">8,0,10,0</Thickness>
-  <Thickness x:Key="ComboBoxItemMargin">3,2,3,0</Thickness>
-  <Thickness x:Key="ComboBoxItemContentMargin">10,8,8,8</Thickness>
-  <system:Double x:Key="ComboBoxChevronSize">11.0</system:Double>
+  <!-- Redefined in .NET 10 -->
+  <!-- <Thickness x:Key="ComboBoxPadding">10,8,10,8</Thickness>
+            <system:Double x:Key="ComboBoxChevronSize">11</system:Double> -->
+  <Thickness x:Key="ComboBoxPadding">12,5,0,7</Thickness>
+  <Thickness x:Key="ComboBoxEditableTextPadding">11,5,38,6</Thickness>
+  <Thickness x:Key="ComboBoxBorderThemeThickness">1,1,1,1</Thickness>
+  <system:Double x:Key="ComboBoxChevronSize">10</system:Double>
   <system:Double x:Key="ComboBoxPopupMinHeight">32.0</system:Double>
   <system:String x:Key="ComboBoxChevronDownGlyph"></system:String>
+  <CornerRadius x:Key="ComboBoxDropDownButtonBackgroundCornerRadius">4</CornerRadius>
+  <Thickness x:Key="ComboBoxItemMargin">3,2,3,0</Thickness>
+  <Thickness x:Key="ComboBoxItemContentMargin">10,8,8,8</Thickness>
   <Style x:Key="DefaultComboBoxTextBoxStyle" TargetType="{x:Type TextBox}">
-    <!--  Focus by parent element  -->
     <Setter Property="FocusVisualStyle" Value="{x:Null}" />
-    <!--  Focus by parent element  -->
-    <!--  Universal WPF UI ContextMenu  -->
     <Setter Property="ContextMenu" Value="{DynamicResource DefaultControlContextMenu}" />
-    <!--  Universal WPF UI ContextMenu  -->
-    <Setter Property="Foreground" Value="{DynamicResource ComboBoxForeground}" />
-    <Setter Property="CaretBrush" Value="{DynamicResource ComboBoxForeground}" />
-    <Setter Property="Background" Value="Transparent" />
-    <Setter Property="Visibility" Value="Hidden" />
+    <Setter Property="Foreground" Value="{DynamicResource TextControlForeground}" />
+    <Setter Property="CaretBrush" Value="{DynamicResource TextControlForeground}" />
+    <Setter Property="BorderBrush" Value="{DynamicResource TextControlElevationBorderBrush}" />
+    <Setter Property="BorderThickness" Value="{DynamicResource TextControlBorderThemeThickness}" />
+    <Setter Property="ScrollViewer.HorizontalScrollBarVisibility" Value="Hidden" />
+    <Setter Property="ScrollViewer.VerticalScrollBarVisibility" Value="Hidden" />
+    <Setter Property="HorizontalContentAlignment" Value="Left" />
+    <Setter Property="VerticalContentAlignment" Value="Top" />
     <Setter Property="Cursor" Value="IBeam" />
-    <Setter Property="Margin" Value="0" />
-    <Setter Property="Padding" Value="0" />
-    <Setter Property="SnapsToDevicePixels" Value="True" />
+    <Setter Property="MinHeight" Value="{DynamicResource TextBoxThemeMinHeight}" />
+    <Setter Property="MinWidth" Value="{DynamicResource TextControlThemeMinWidth}" />
+    <Setter Property="Padding" Value="{DynamicResource TextControlThemePadding}" />
+    <Setter Property="Border.CornerRadius" Value="{DynamicResource ControlCornerRadius}" />
+    <Setter Property="AllowDrop" Value="True" />
+    <Setter Property="ScrollViewer.PanningMode" Value="VerticalFirst" />
+    <Setter Property="Stylus.IsFlicksEnabled" Value="False" />
     <Setter Property="OverridesDefaultStyle" Value="True" />
+    <Setter Property="SelectionBrush" Value="{DynamicResource TextControlSelectionHighlightColor}" />
     <Setter Property="Template">
       <Setter.Value>
-        <ControlTemplate TargetType="{x:Type TextBox}">
-          <Decorator x:Name="PART_ContentHost" Margin="{TemplateBinding Padding}" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" TextElement.Foreground="{TemplateBinding Foreground}" />
+        <ControlTemplate TargetType="{x:Type TextBoxBase}">
+          <Grid>
+            <Border x:Name="ContentBorder" MinWidth="{TemplateBinding MinWidth}" MinHeight="{TemplateBinding MinHeight}" Background="{TemplateBinding Background}" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" CornerRadius="{TemplateBinding Border.CornerRadius}" />
+            <ScrollViewer x:Name="PART_ContentHost" Margin="{TemplateBinding BorderThickness}" CanContentScroll="{TemplateBinding ScrollViewer.CanContentScroll}" HorizontalScrollBarVisibility="{TemplateBinding ScrollViewer.HorizontalScrollBarVisibility}" IsDeferredScrollingEnabled="{TemplateBinding ScrollViewer.IsDeferredScrollingEnabled}" IsTabStop="{TemplateBinding ScrollViewer.IsTabStop}" Padding="{TemplateBinding Padding}" TextElement.Foreground="{TemplateBinding Foreground}" VerticalScrollBarVisibility="{TemplateBinding ScrollViewer.VerticalScrollBarVisibility}" />
+          </Grid>
+          <ControlTemplate.Triggers>
+            <Trigger Property="IsMouseOver" Value="True">
+              <!-- Disabling this setter as this will be handled by the ComboBox style. -->
+              <!--<Setter TargetName="ContentBorder" Property="Background" Value="{DynamicResource TextControlBackgroundPointerOver}" />-->
+              <Setter TargetName="ContentBorder" Property="BorderBrush" Value="{DynamicResource TextControlBorderBrushPointerOver}" />
+              <Setter TargetName="PART_ContentHost" Property="Foreground" Value="{DynamicResource TextControlForegroundPointerOver}" />
+            </Trigger>
+            <Trigger Property="IsFocused" Value="True">
+              <Setter TargetName="ContentBorder" Property="BorderThickness" Value="{DynamicResource TextControlBorderThemeThicknessFocused}" />
+              <Setter TargetName="ContentBorder" Property="Background" Value="{DynamicResource TextControlBackgroundFocused}" />
+              <Setter TargetName="ContentBorder" Property="BorderBrush" Value="{DynamicResource TextControlBorderBrushFocused}" />
+              <Setter TargetName="PART_ContentHost" Property="Foreground" Value="{DynamicResource TextControlForegroundFocused}" />
+            </Trigger>
+            <Trigger Property="IsEnabled" Value="False">
+              <Setter TargetName="ContentBorder" Property="Background" Value="{DynamicResource TextControlBackgroundDisabled}" />
+              <Setter TargetName="ContentBorder" Property="BorderBrush" Value="{DynamicResource TextControlBorderBrushDisabled}" />
+              <Setter TargetName="PART_ContentHost" Property="Foreground" Value="{DynamicResource TextControlForegroundDisabled}" />
+            </Trigger>
+          </ControlTemplate.Triggers>
         </ControlTemplate>
       </Setter.Value>
     </Setter>
   </Style>
   <Style x:Key="DefaultComboBoxToggleButtonStyle" TargetType="{x:Type ToggleButton}">
-    <!--  Focus by parent element  -->
     <Setter Property="FocusVisualStyle" Value="{x:Null}" />
-    <!--  Focus by parent element  -->
     <Setter Property="Foreground" Value="{DynamicResource ComboBoxForeground}" />
     <Setter Property="Background" Value="Transparent" />
     <Setter Property="BorderBrush" Value="Transparent" />
-    <Setter Property="BorderThickness" Value="0" />
-    <Setter Property="Border.CornerRadius" Value="0" />
-    <Setter Property="SnapsToDevicePixels" Value="True" />
+    <Setter Property="Border.CornerRadius" Value="{DynamicResource ControlCornerRadius}" />
     <Setter Property="OverridesDefaultStyle" Value="True" />
     <Setter Property="Template">
       <Setter.Value>
@@ -744,14 +771,217 @@
       </Setter.Value>
     </Setter>
   </Style>
+  <ControlTemplate x:Key="DefaultComboBoxTemplate" TargetType="{x:Type ComboBox}">
+    <Grid x:Name="LayoutGrid">
+      <Grid.ColumnDefinitions>
+        <ColumnDefinition Width="*" />
+        <ColumnDefinition Width="38" />
+      </Grid.ColumnDefinitions>
+      <Border x:Name="ContentBorder" Grid.ColumnSpan="2" Background="{TemplateBinding Background}" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" CornerRadius="{TemplateBinding Border.CornerRadius}" />
+      <ContentPresenter Name="PART_ContentPresenter" Content="{TemplateBinding SelectionBoxItem}" ContentTemplate="{TemplateBinding SelectionBoxItemTemplate}" ContentTemplateSelector="{TemplateBinding ItemTemplateSelector}" ContentStringFormat="{TemplateBinding SelectionBoxItemStringFormat}" Margin="{TemplateBinding Padding}" TextElement.Foreground="{TemplateBinding Foreground}" HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" VerticalAlignment="{TemplateBinding VerticalContentAlignment}" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" IsHitTestVisible="False" />
+      <ToggleButton x:Name="ToggleButton" Grid.ColumnSpan="2" Focusable="False" IsChecked="{Binding Path=IsDropDownOpen, Mode=TwoWay, RelativeSource={RelativeSource TemplatedParent}}" Style="{StaticResource DefaultComboBoxToggleButtonStyle}" />
+      <TextBlock x:Name="ChevronIcon" Grid.Column="1" HorizontalAlignment="Center" VerticalAlignment="Center" IsHitTestVisible="False" RenderTransformOrigin="0.5,0.5" FontFamily="{DynamicResource SymbolThemeFontFamily}" FontSize="{StaticResource ComboBoxChevronSize}" Text="{StaticResource ComboBoxChevronDownGlyph}">
+        <TextBlock.RenderTransform>
+          <RotateTransform Angle="0" />
+        </TextBlock.RenderTransform>
+      </TextBlock>
+      <Popup x:Name="PART_Popup" MinWidth="{TemplateBinding ActualWidth}" AllowsTransparency="True" Focusable="False" IsOpen="{TemplateBinding IsDropDownOpen}" Placement="{TemplateBinding Popup.Placement}" PopupAnimation="{TemplateBinding Popup.PopupAnimation}" VerticalOffset="1">
+        <Border x:Name="DropDownBorder" Padding="0,4,0,6" Background="{DynamicResource ComboBoxDropDownBackground}" BorderBrush="{DynamicResource ComboBoxDropDownBorderBrush}" BorderThickness="1.5" CornerRadius="{DynamicResource PopupCornerRadius}" SnapsToDevicePixels="True">
+          <Border.RenderTransform>
+            <TranslateTransform />
+          </Border.RenderTransform>
+          <Grid>
+            <ScrollViewer MaxHeight="{TemplateBinding MaxDropDownHeight}" SnapsToDevicePixels="True" HorizontalScrollBarVisibility="{TemplateBinding ScrollViewer.HorizontalScrollBarVisibility}" VerticalScrollBarVisibility="{TemplateBinding ScrollViewer.VerticalScrollBarVisibility}" TextElement.FontSize="{TemplateBinding FontSize}" TextElement.FontWeight="{TemplateBinding FontWeight}" TextElement.Foreground="{TemplateBinding Foreground}">
+              <StackPanel IsItemsHost="True" KeyboardNavigation.DirectionalNavigation="Contained" />
+            </ScrollViewer>
+          </Grid>
+          <Border.Effect>
+            <DropShadowEffect BlurRadius="20" Direction="270" Opacity="0.25" ShadowDepth="6" />
+          </Border.Effect>
+        </Border>
+      </Popup>
+    </Grid>
+    <ControlTemplate.Triggers>
+      <Trigger Property="IsDropDownOpen" Value="True">
+        <Trigger.EnterActions>
+          <BeginStoryboard>
+            <Storyboard>
+              <DoubleAnimation Storyboard.TargetName="ChevronIcon" Storyboard.TargetProperty="(TextBlock.RenderTransform).(RotateTransform.Angle)" From="0" To="180" Duration="00:00:00.167" />
+              <DoubleAnimation Storyboard.TargetName="DropDownBorder" Storyboard.TargetProperty="(Border.RenderTransform).(TranslateTransform.Y)" From="-90" To="0" Duration="00:00:00.167">
+                <DoubleAnimation.EasingFunction>
+                  <CircleEase EasingMode="EaseOut" />
+                </DoubleAnimation.EasingFunction>
+              </DoubleAnimation>
+            </Storyboard>
+          </BeginStoryboard>
+        </Trigger.EnterActions>
+        <Trigger.ExitActions>
+          <BeginStoryboard>
+            <Storyboard>
+              <DoubleAnimation Storyboard.TargetName="ChevronIcon" Storyboard.TargetProperty="(TextBlock.RenderTransform).(RotateTransform.Angle)" From="180" To="0" Duration="00:00:00.167" />
+            </Storyboard>
+          </BeginStoryboard>
+        </Trigger.ExitActions>
+      </Trigger>
+      <Trigger Property="HasItems" Value="False">
+        <Setter TargetName="DropDownBorder" Property="MinHeight" Value="{StaticResource ComboBoxPopupMinHeight}" />
+      </Trigger>
+      <Trigger SourceName="PART_Popup" Property="Popup.AllowsTransparency" Value="False">
+        <Setter TargetName="DropDownBorder" Property="CornerRadius" Value="0" />
+      </Trigger>
+      <Trigger Property="IsGrouping" Value="True">
+        <Setter Property="ScrollViewer.CanContentScroll" Value="False" />
+      </Trigger>
+      <!--PointerOver state-->
+      <Trigger Property="IsMouseOver" Value="True">
+        <Setter TargetName="ContentBorder" Property="Background" Value="{DynamicResource ComboBoxBackgroundPointerOver}" />
+        <Setter TargetName="ContentBorder" Property="BorderBrush" Value="{DynamicResource ComboBoxBorderBrushPointerOver}" />
+        <Setter TargetName="PART_ContentPresenter" Property="TextElement.Foreground" Value="{DynamicResource ComboBoxForegroundPointerOver}" />
+      </Trigger>
+      <!--Pressed state-->
+      <Trigger SourceName="ToggleButton" Property="IsPressed" Value="True">
+        <Setter TargetName="ContentBorder" Property="Background" Value="{DynamicResource ComboBoxBackgroundPressed}" />
+        <Setter TargetName="ContentBorder" Property="BorderBrush" Value="{DynamicResource ComboBoxBorderBrushPressed}" />
+        <Setter TargetName="PART_ContentPresenter" Property="TextElement.Foreground" Value="{DynamicResource ComboBoxForegroundPressed}" />
+      </Trigger>
+      <!--Focused state-->
+      <Trigger Property="IsFocused" Value="True">
+        <Setter TargetName="PART_ContentPresenter" Property="TextElement.Foreground" Value="{DynamicResource ComboBoxForegroundFocused}" />
+        <Setter TargetName="ChevronIcon" Property="Foreground" Value="{DynamicResource ComboBoxDropDownGlyphForegroundFocused}" />
+      </Trigger>
+      <!--FocusedPressed state-->
+      <MultiTrigger>
+        <MultiTrigger.Conditions>
+          <Condition Property="IsFocused" Value="True" />
+          <Condition SourceName="ToggleButton" Property="IsPressed" Value="True" />
+        </MultiTrigger.Conditions>
+        <Setter TargetName="PART_ContentPresenter" Property="TextElement.Foreground" Value="{DynamicResource ComboBoxForegroundFocusedPressed}" />
+        <Setter TargetName="ChevronIcon" Property="Foreground" Value="{DynamicResource ComboBoxDropDownGlyphForegroundFocusedPressed}" />
+      </MultiTrigger>
+      <!--Disabled state-->
+      <Trigger Property="IsEnabled" Value="False">
+        <Setter TargetName="ContentBorder" Property="Background" Value="{DynamicResource ComboBoxBackgroundDisabled}" />
+        <Setter TargetName="ContentBorder" Property="BorderBrush" Value="{DynamicResource ComboBoxBorderBrushDisabled}" />
+        <Setter TargetName="PART_ContentPresenter" Property="TextElement.Foreground" Value="{DynamicResource ComboBoxForegroundDisabled}" />
+        <Setter TargetName="ChevronIcon" Property="Foreground" Value="{DynamicResource ComboBoxDropDownGlyphForegroundDisabled}" />
+      </Trigger>
+    </ControlTemplate.Triggers>
+  </ControlTemplate>
+  <ControlTemplate x:Key="EditableComboBoxTemplate" TargetType="{x:Type ComboBox}">
+    <Grid x:Name="LayoutGrid">
+      <Grid.ColumnDefinitions>
+        <ColumnDefinition Width="*" />
+        <ColumnDefinition Width="38" />
+      </Grid.ColumnDefinitions>
+      <Border x:Name="ContentBorder" Grid.ColumnSpan="2" Background="{TemplateBinding Background}" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" CornerRadius="{TemplateBinding Border.CornerRadius}" />
+      <TextBox x:Name="PART_EditableTextBox" Grid.ColumnSpan="2" Padding="11,5,38,6" Foreground="{TemplateBinding Foreground}" FontSize="{TemplateBinding FontSize}" IsReadOnly="{TemplateBinding IsReadOnly}" Style="{StaticResource DefaultComboBoxTextBoxStyle}" AutomationProperties.Name="{TemplateBinding AutomationProperties.Name}" />
+      <Border x:Name="DropDownOverlay" Grid.Column="1" Margin="4" Width="30" Background="Transparent" CornerRadius="{StaticResource ComboBoxDropDownButtonBackgroundCornerRadius}" />
+      <ToggleButton x:Name="ToggleButton" Grid.Column="1" Margin="4" Focusable="False" IsChecked="{Binding Path=IsDropDownOpen, Mode=TwoWay, RelativeSource={RelativeSource TemplatedParent}}" Style="{StaticResource DefaultComboBoxToggleButtonStyle}" />
+      <TextBlock x:Name="ChevronIcon" Grid.Column="1" HorizontalAlignment="Center" VerticalAlignment="Center" IsHitTestVisible="False" RenderTransformOrigin="0.5,0.5" FontFamily="{DynamicResource SymbolThemeFontFamily}" FontSize="{StaticResource ComboBoxChevronSize}" Text="{StaticResource ComboBoxChevronDownGlyph}">
+        <TextBlock.RenderTransform>
+          <RotateTransform Angle="0" />
+        </TextBlock.RenderTransform>
+      </TextBlock>
+      <Popup x:Name="PART_Popup" Focusable="False" AllowsTransparency="True" MinWidth="{TemplateBinding ActualWidth}" IsOpen="{TemplateBinding IsDropDownOpen}" Placement="{TemplateBinding Popup.Placement}" PopupAnimation="{TemplateBinding Popup.PopupAnimation}" VerticalOffset="1">
+        <Border x:Name="DropDownBorder" Padding="0,4,0,6" BorderThickness="1.5" Background="{DynamicResource ComboBoxDropDownBackground}" BorderBrush="{DynamicResource ComboBoxDropDownBorderBrush}" CornerRadius="{DynamicResource PopupCornerRadius}" SnapsToDevicePixels="True">
+          <Border.RenderTransform>
+            <TranslateTransform />
+          </Border.RenderTransform>
+          <Grid>
+            <ScrollViewer MaxHeight="{TemplateBinding MaxDropDownHeight}" SnapsToDevicePixels="True" HorizontalScrollBarVisibility="{TemplateBinding ScrollViewer.HorizontalScrollBarVisibility}" VerticalScrollBarVisibility="{TemplateBinding ScrollViewer.VerticalScrollBarVisibility}" TextElement.FontSize="{TemplateBinding FontSize}" TextElement.FontWeight="{TemplateBinding FontWeight}" TextElement.Foreground="{TemplateBinding Foreground}">
+              <StackPanel IsItemsHost="True" KeyboardNavigation.DirectionalNavigation="Contained" />
+            </ScrollViewer>
+          </Grid>
+          <Border.Effect>
+            <DropShadowEffect BlurRadius="20" Direction="270" Opacity="0.25" ShadowDepth="6" />
+          </Border.Effect>
+        </Border>
+      </Popup>
+    </Grid>
+    <ControlTemplate.Triggers>
+      <Trigger Property="IsDropDownOpen" Value="True">
+        <Trigger.EnterActions>
+          <BeginStoryboard>
+            <Storyboard>
+              <DoubleAnimation Storyboard.TargetName="ChevronIcon" Storyboard.TargetProperty="(TextBlock.RenderTransform).(RotateTransform.Angle)" From="0" To="180" Duration="00:00:00.167" />
+              <DoubleAnimation Storyboard.TargetName="DropDownBorder" Storyboard.TargetProperty="(Border.RenderTransform).(TranslateTransform.Y)" From="-90" To="0" Duration="00:00:00.167">
+                <DoubleAnimation.EasingFunction>
+                  <CircleEase EasingMode="EaseOut" />
+                </DoubleAnimation.EasingFunction>
+              </DoubleAnimation>
+            </Storyboard>
+          </BeginStoryboard>
+        </Trigger.EnterActions>
+        <Trigger.ExitActions>
+          <BeginStoryboard>
+            <Storyboard>
+              <DoubleAnimation Storyboard.TargetName="ChevronIcon" Storyboard.TargetProperty="(TextBlock.RenderTransform).(RotateTransform.Angle)" From="180" To="0" Duration="00:00:00.167" />
+            </Storyboard>
+          </BeginStoryboard>
+        </Trigger.ExitActions>
+      </Trigger>
+      <Trigger Property="HasItems" Value="False">
+        <Setter TargetName="DropDownBorder" Property="MinHeight" Value="{StaticResource ComboBoxPopupMinHeight}" />
+      </Trigger>
+      <Trigger SourceName="PART_Popup" Property="Popup.AllowsTransparency" Value="False">
+        <Setter TargetName="DropDownBorder" Property="CornerRadius" Value="0" />
+      </Trigger>
+      <Trigger Property="IsGrouping" Value="True">
+        <Setter Property="ScrollViewer.CanContentScroll" Value="False" />
+      </Trigger>
+      <!-- PointerOver state-->
+      <Trigger Property="IsMouseOver" Value="True">
+        <Setter TargetName="ContentBorder" Property="Background" Value="{DynamicResource ComboBoxBackgroundPointerOver}" />
+        <Setter TargetName="ContentBorder" Property="BorderBrush" Value="{DynamicResource ComboBoxBorderBrushPointerOver}" />
+        <Setter TargetName="PART_EditableTextBox" Property="TextElement.Foreground" Value="{DynamicResource ComboBoxForegroundPointerOver}" />
+      </Trigger>
+      <!-- Focused / TextBoxFocused -->
+      <Trigger Property="IsFocused" Value="True">
+        <Setter TargetName="PART_EditableTextBox" Property="TextElement.Foreground" Value="{DynamicResource ComboBoxForegroundFocused}" />
+        <Setter TargetName="ChevronIcon" Property="Foreground" Value="{DynamicResource ComboBoxEditableDropDownGlyphForeground}" />
+      </Trigger>
+      <!--TextBoxOverlayPointerOver state-->
+      <Trigger SourceName="ToggleButton" Property="IsMouseOver" Value="True">
+        <Setter TargetName="DropDownOverlay" Property="Background" Value="{DynamicResource ComboBoxDropDownBackgroundPointerOver}" />
+      </Trigger>
+      <!--TextBoxOverlayPressed-->
+      <Trigger SourceName="ToggleButton" Property="IsPressed" Value="True">
+        <Setter TargetName="DropDownOverlay" Property="Background" Value="{DynamicResource ComboBoxDropDownBackgroundPointerPressed}" />
+      </Trigger>
+      <!--TextBoxFocusedOverlayPointerOver state-->
+      <MultiTrigger>
+        <MultiTrigger.Conditions>
+          <Condition Property="IsFocused" Value="True" />
+          <Condition SourceName="ToggleButton" Property="IsMouseOver" Value="True" />
+        </MultiTrigger.Conditions>
+        <Setter TargetName="DropDownOverlay" Property="Background" Value="{DynamicResource ComboBoxDropDownBackgroundPointerOver}" />
+        <Setter TargetName="ChevronIcon" Property="Foreground" Value="{DynamicResource ComboBoxEditableDropDownGlyphForeground}" />
+      </MultiTrigger>
+      <!-- FocusedPressed state / TextBoxFocusedOverlayPressed state -->
+      <MultiTrigger>
+        <MultiTrigger.Conditions>
+          <Condition Property="IsFocused" Value="True" />
+          <Condition SourceName="ToggleButton" Property="IsPressed" Value="True" />
+        </MultiTrigger.Conditions>
+        <Setter TargetName="ChevronIcon" Property="Foreground" Value="{DynamicResource ComboBoxEditableDropDownGlyphForeground}" />
+        <Setter TargetName="PART_EditableTextBox" Property="TextElement.Foreground" Value="{DynamicResource ComboBoxForegroundFocusedPressed}" />
+        <Setter TargetName="DropDownOverlay" Property="Background" Value="{DynamicResource ComboBoxFocusedDropDownBackgroundPointerPressed}" />
+      </MultiTrigger>
+      <!--Disabled state-->
+      <Trigger Property="IsEnabled" Value="False">
+        <Setter TargetName="ContentBorder" Property="Background" Value="{DynamicResource ComboBoxBackgroundDisabled}" />
+        <Setter TargetName="ContentBorder" Property="BorderBrush" Value="{DynamicResource ComboBoxBorderBrushDisabled}" />
+        <Setter TargetName="PART_EditableTextBox" Property="TextElement.Foreground" Value="{DynamicResource ComboBoxForegroundDisabled}" />
+        <Setter TargetName="ChevronIcon" Property="Foreground" Value="{DynamicResource ComboBoxDropDownGlyphForegroundDisabled}" />
+      </Trigger>
+    </ControlTemplate.Triggers>
+  </ControlTemplate>
   <Style x:Key="DefaultComboBoxStyle" TargetType="{x:Type ComboBox}">
-    <!--  Universal WPF UI focus  -->
     <Setter Property="FocusVisualStyle" Value="{DynamicResource DefaultControlFocusVisualStyle}" />
-    <!--  Universal WPF UI ContextMenu  -->
     <Setter Property="ContextMenu" Value="{DynamicResource DefaultControlContextMenu}" />
     <Setter Property="Foreground" Value="{DynamicResource ComboBoxForeground}" />
     <Setter Property="Background" Value="{DynamicResource ComboBoxBackground}" />
-    <Setter Property="BorderBrush" Value="{DynamicResource ControlElevationBorderBrush}" />
+    <Setter Property="BorderBrush" Value="{DynamicResource ComboBoxBorderBrush}" />
     <Setter Property="BorderThickness" Value="{StaticResource ComboBoxBorderThemeThickness}" />
     <Setter Property="ScrollViewer.CanContentScroll" Value="False" />
     <Setter Property="ScrollViewer.HorizontalScrollBarVisibility" Value="Auto" />
@@ -766,125 +996,15 @@
     <Setter Property="Padding" Value="{DynamicResource ComboBoxPadding}" />
     <Setter Property="Border.CornerRadius" Value="{DynamicResource ControlCornerRadius}" />
     <Setter Property="Popup.PopupAnimation" Value="None" />
-    <!--  WPF doesn't like centering, the animation is ugly and the mouse button sometimes clicks right away.  -->
     <Setter Property="Popup.Placement" Value="Bottom" />
     <Setter Property="SnapsToDevicePixels" Value="True" />
     <Setter Property="OverridesDefaultStyle" Value="True" />
-    <Setter Property="Template">
-      <Setter.Value>
-        <ControlTemplate TargetType="{x:Type ComboBox}">
-          <Grid>
-            <Border x:Name="ContentBorder" Grid.Row="0" MinWidth="{TemplateBinding MinWidth}" MinHeight="{TemplateBinding MinHeight}" Padding="0" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" Background="{TemplateBinding Background}" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" CornerRadius="{TemplateBinding Border.CornerRadius}">
-              <Grid HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" VerticalAlignment="{TemplateBinding VerticalContentAlignment}">
-                <!--
-                                    Funky grid - because:
-                                    Chevron is over Presenter, ToggleButton is over Chevron, TextBox is over ToggleButton.
-                                    But, TextBox is not over Chevron, so ToggleButton still works.
-                                -->
-                <Grid>
-                  <Grid.ColumnDefinitions>
-                    <ColumnDefinition Width="*" />
-                    <ColumnDefinition Width="Auto" />
-                  </Grid.ColumnDefinitions>
-                  <Grid Grid.Column="0" Margin="{TemplateBinding Padding}">
-                    <ContentPresenter Name="PART_ContentPresenter" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" Content="{TemplateBinding SelectionBoxItem}" ContentTemplate="{TemplateBinding SelectionBoxItemTemplate}" ContentTemplateSelector="{TemplateBinding ItemTemplateSelector}" ContentStringFormat="{TemplateBinding SelectionBoxItemStringFormat}" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" IsHitTestVisible="False" TextElement.Foreground="{TemplateBinding Foreground}" />
-                  </Grid>
-                  <Grid Grid.Column="1" Margin="{StaticResource ComboBoxChevronMargin}">
-                    <TextBlock x:Name="ChevronIcon" Margin="0" VerticalAlignment="Center" FontSize="{StaticResource ComboBoxChevronSize}" Foreground="{DynamicResource ComboBoxDropDownGlyphForeground}" RenderTransformOrigin="0.5, 0.5" FontFamily="{DynamicResource SymbolThemeFontFamily}" Text="{StaticResource ComboBoxChevronDownGlyph}">
-                      <TextBlock.RenderTransform>
-                        <RotateTransform Angle="0" />
-                      </TextBlock.RenderTransform>
-                    </TextBlock>
-                  </Grid>
-                  <Grid Grid.Column="0" Grid.ColumnSpan="2" Margin="0">
-                    <ToggleButton Name="ToggleButton" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" ClickMode="Press" Focusable="False" Foreground="{TemplateBinding Foreground}" IsChecked="{Binding Path=IsDropDownOpen, Mode=TwoWay, RelativeSource={RelativeSource TemplatedParent}}" Style="{StaticResource DefaultComboBoxToggleButtonStyle}" />
-                  </Grid>
-                  <Grid Grid.Column="0" Margin="{TemplateBinding Padding}">
-                    <TextBox x:Name="PART_EditableTextBox" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" FontSize="{TemplateBinding FontSize}" Foreground="{TemplateBinding Foreground}" IsReadOnly="{TemplateBinding IsReadOnly}" Style="{StaticResource DefaultComboBoxTextBoxStyle}" AutomationProperties.Name="{TemplateBinding AutomationProperties.Name}" />
-                  </Grid>
-                </Grid>
-                <Popup x:Name="PART_Popup" MinWidth="{TemplateBinding ActualWidth}" VerticalAlignment="Center" AllowsTransparency="True" Focusable="False" IsOpen="{TemplateBinding IsDropDownOpen}" Placement="{TemplateBinding Popup.Placement}" PopupAnimation="{TemplateBinding Popup.PopupAnimation}" VerticalOffset="1">
-                  <Border x:Name="DropDownBorder" Padding="0,4,0,6" Background="{DynamicResource ComboBoxDropDownBackground}" BorderBrush="{DynamicResource ComboBoxDropDownBorderBrush}" BorderThickness="1.5" CornerRadius="{DynamicResource PopupCornerRadius}" SnapsToDevicePixels="True">
-                    <!--Will revist this code while doing performance evaluation for dynamic resources.-->
-                    <Border.RenderTransform>
-                      <TranslateTransform />
-                    </Border.RenderTransform>
-                    <Grid>
-                      <ScrollViewer MaxHeight="{TemplateBinding MaxDropDownHeight}" Margin="0" HorizontalScrollBarVisibility="{TemplateBinding ScrollViewer.HorizontalScrollBarVisibility}" SnapsToDevicePixels="True" TextElement.FontSize="{TemplateBinding FontSize}" TextElement.FontWeight="{TemplateBinding FontWeight}" TextElement.Foreground="{TemplateBinding Foreground}" VerticalScrollBarVisibility="{TemplateBinding ScrollViewer.VerticalScrollBarVisibility}">
-                        <StackPanel IsItemsHost="True" KeyboardNavigation.DirectionalNavigation="Contained" TextElement.FontSize="{TemplateBinding FontSize}" />
-                      </ScrollViewer>
-                    </Grid>
-                    <Border.Effect>
-                      <DropShadowEffect BlurRadius="20" Direction="270" Opacity="0.25" ShadowDepth="6" />
-                    </Border.Effect>
-                  </Border>
-                </Popup>
-              </Grid>
-            </Border>
-            <Border x:Name="AccentBorder" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" BorderBrush="{DynamicResource ComboBoxBorderBrushFocused}" BorderThickness="{StaticResource ComboBoxAccentBorderThemeThickness}" CornerRadius="{TemplateBinding Border.CornerRadius}" Visibility="Collapsed" />
-          </Grid>
-          <ControlTemplate.Triggers>
-            <Trigger Property="IsDropDownOpen" Value="True">
-              <Trigger.EnterActions>
-                <BeginStoryboard>
-                  <Storyboard>
-                    <DoubleAnimation Storyboard.TargetName="ChevronIcon" Storyboard.TargetProperty="(TextBlock.RenderTransform).(RotateTransform.Angle)" From="0" To="180" Duration="00:00:00.167" />
-                    <DoubleAnimation Storyboard.TargetName="DropDownBorder" Storyboard.TargetProperty="(Border.RenderTransform).(TranslateTransform.Y)" From="-90" To="0" Duration="00:00:00.167">
-                      <DoubleAnimation.EasingFunction>
-                        <CircleEase EasingMode="EaseOut" />
-                      </DoubleAnimation.EasingFunction>
-                    </DoubleAnimation>
-                  </Storyboard>
-                </BeginStoryboard>
-              </Trigger.EnterActions>
-              <Trigger.ExitActions>
-                <BeginStoryboard>
-                  <Storyboard>
-                    <DoubleAnimation Storyboard.TargetName="ChevronIcon" Storyboard.TargetProperty="(TextBlock.RenderTransform).(RotateTransform.Angle)" From="180" To="0" Duration="00:00:00.167" />
-                  </Storyboard>
-                </BeginStoryboard>
-              </Trigger.ExitActions>
-            </Trigger>
-            <Trigger Property="HasItems" Value="False">
-              <Setter TargetName="DropDownBorder" Property="MinHeight" Value="{StaticResource ComboBoxPopupMinHeight}" />
-            </Trigger>
-            <Trigger SourceName="PART_Popup" Property="Popup.AllowsTransparency" Value="False">
-              <Setter TargetName="DropDownBorder" Property="CornerRadius" Value="0" />
-            </Trigger>
-            <Trigger Property="IsGrouping" Value="True">
-              <Setter Property="ScrollViewer.CanContentScroll" Value="False" />
-            </Trigger>
-            <Trigger Property="IsEditable" Value="True">
-              <Setter Property="IsTabStop" Value="False" />
-              <Setter TargetName="PART_EditableTextBox" Property="Visibility" Value="Visible" />
-              <Setter TargetName="PART_ContentPresenter" Property="Visibility" Value="Hidden" />
-            </Trigger>
-            <MultiTrigger>
-              <MultiTrigger.Conditions>
-                <Condition Property="IsEnabled" Value="True" />
-                <Condition Property="IsKeyboardFocusWithin" Value="True" />
-                <Condition Property="IsEditable" Value="True" />
-              </MultiTrigger.Conditions>
-              <Setter TargetName="ContentBorder" Property="Background" Value="{DynamicResource ComboBoxBackgroundFocused}" />
-              <Setter TargetName="AccentBorder" Property="Visibility" Value="Visible" />
-            </MultiTrigger>
-            <MultiTrigger>
-              <MultiTrigger.Conditions>
-                <Condition Property="IsEnabled" Value="True" />
-                <Condition Property="IsMouseOver" Value="True" />
-                <Condition Property="IsKeyboardFocusWithin" Value="False" />
-              </MultiTrigger.Conditions>
-              <Setter TargetName="ContentBorder" Property="Background" Value="{DynamicResource ComboBoxBackgroundPointerOver}" />
-            </MultiTrigger>
-            <Trigger Property="IsEnabled" Value="False">
-              <Setter TargetName="ContentBorder" Property="Background" Value="{DynamicResource ComboBoxBackgroundDisabled}" />
-              <Setter TargetName="ContentBorder" Property="BorderBrush" Value="{DynamicResource ComboBoxBorderBrushDisabled}" />
-              <Setter Property="Foreground" Value="{DynamicResource ComboBoxForegroundDisabled}" />
-            </Trigger>
-          </ControlTemplate.Triggers>
-        </ControlTemplate>
-      </Setter.Value>
-    </Setter>
+    <Setter Property="Template" Value="{StaticResource DefaultComboBoxTemplate}" />
+    <Style.Triggers>
+      <Trigger Property="IsEditable" Value="True">
+        <Setter Property="Template" Value="{StaticResource EditableComboBoxTemplate}" />
+      </Trigger>
+    </Style.Triggers>
   </Style>
   <Style BasedOn="{StaticResource DefaultComboBoxItemStyle}" TargetType="{x:Type ComboBoxItem}" />
   <Style BasedOn="{StaticResource DefaultComboBoxStyle}" TargetType="{x:Type ComboBox}" />

From 79605c0aaba5cc1abfc0e4e915e8aea13cc42af0 Mon Sep 17 00:00:00 2001
From: dipeshmsft <dipeshkumar@microsoft.com>
Date: Tue, 3 Jun 2025 15:52:06 +0530
Subject: [PATCH 6/6] Reintroduced ComboBox popup grouping fix #10878

---
 .../Themes/PresentationFramework.Fluent/Styles/ComboBox.xaml  | 4 ++--
 .../PresentationFramework.Fluent/Themes/Fluent.Dark.xaml      | 4 ++--
 .../Themes/PresentationFramework.Fluent/Themes/Fluent.HC.xaml | 4 ++--
 .../PresentationFramework.Fluent/Themes/Fluent.Light.xaml     | 4 ++--
 .../Themes/PresentationFramework.Fluent/Themes/Fluent.xaml    | 4 ++--
 5 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Styles/ComboBox.xaml b/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Styles/ComboBox.xaml
index b16f5ec5aaa..efd0ddafe3e 100644
--- a/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Styles/ComboBox.xaml
+++ b/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Styles/ComboBox.xaml
@@ -258,7 +258,7 @@
                                       TextElement.FontSize="{TemplateBinding FontSize}"
                                       TextElement.FontWeight="{TemplateBinding FontWeight}"
                                       TextElement.Foreground="{TemplateBinding Foreground}">
-                            <StackPanel IsItemsHost="True"
+                            <ItemsPresenter
                                         KeyboardNavigation.DirectionalNavigation="Contained" />
                         </ScrollViewer>
                     </Grid>
@@ -438,7 +438,7 @@
                                       TextElement.FontSize="{TemplateBinding FontSize}"
                                       TextElement.FontWeight="{TemplateBinding FontWeight}"
                                       TextElement.Foreground="{TemplateBinding Foreground}">
-                            <StackPanel IsItemsHost="True"
+                            <ItemsPresenter
                                         KeyboardNavigation.DirectionalNavigation="Contained" />
                         </ScrollViewer>
                     </Grid>
diff --git a/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.Dark.xaml b/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.Dark.xaml
index a51b384fc8f..b6cab69496a 100644
--- a/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.Dark.xaml
+++ b/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.Dark.xaml
@@ -1565,7 +1565,7 @@
           </Border.RenderTransform>
           <Grid>
             <ScrollViewer MaxHeight="{TemplateBinding MaxDropDownHeight}" SnapsToDevicePixels="True" HorizontalScrollBarVisibility="{TemplateBinding ScrollViewer.HorizontalScrollBarVisibility}" VerticalScrollBarVisibility="{TemplateBinding ScrollViewer.VerticalScrollBarVisibility}" TextElement.FontSize="{TemplateBinding FontSize}" TextElement.FontWeight="{TemplateBinding FontWeight}" TextElement.Foreground="{TemplateBinding Foreground}">
-              <StackPanel IsItemsHost="True" KeyboardNavigation.DirectionalNavigation="Contained" />
+              <ItemsPresenter KeyboardNavigation.DirectionalNavigation="Contained" />
             </ScrollViewer>
           </Grid>
           <Border.Effect>
@@ -1662,7 +1662,7 @@
           </Border.RenderTransform>
           <Grid>
             <ScrollViewer MaxHeight="{TemplateBinding MaxDropDownHeight}" SnapsToDevicePixels="True" HorizontalScrollBarVisibility="{TemplateBinding ScrollViewer.HorizontalScrollBarVisibility}" VerticalScrollBarVisibility="{TemplateBinding ScrollViewer.VerticalScrollBarVisibility}" TextElement.FontSize="{TemplateBinding FontSize}" TextElement.FontWeight="{TemplateBinding FontWeight}" TextElement.Foreground="{TemplateBinding Foreground}">
-              <StackPanel IsItemsHost="True" KeyboardNavigation.DirectionalNavigation="Contained" />
+              <ItemsPresenter KeyboardNavigation.DirectionalNavigation="Contained" />
             </ScrollViewer>
           </Grid>
           <Border.Effect>
diff --git a/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.HC.xaml b/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.HC.xaml
index 2df2fe51146..71a7c57f07b 100644
--- a/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.HC.xaml
+++ b/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.HC.xaml
@@ -1468,7 +1468,7 @@
           </Border.RenderTransform>
           <Grid>
             <ScrollViewer MaxHeight="{TemplateBinding MaxDropDownHeight}" SnapsToDevicePixels="True" HorizontalScrollBarVisibility="{TemplateBinding ScrollViewer.HorizontalScrollBarVisibility}" VerticalScrollBarVisibility="{TemplateBinding ScrollViewer.VerticalScrollBarVisibility}" TextElement.FontSize="{TemplateBinding FontSize}" TextElement.FontWeight="{TemplateBinding FontWeight}" TextElement.Foreground="{TemplateBinding Foreground}">
-              <StackPanel IsItemsHost="True" KeyboardNavigation.DirectionalNavigation="Contained" />
+              <ItemsPresenter KeyboardNavigation.DirectionalNavigation="Contained" />
             </ScrollViewer>
           </Grid>
           <Border.Effect>
@@ -1565,7 +1565,7 @@
           </Border.RenderTransform>
           <Grid>
             <ScrollViewer MaxHeight="{TemplateBinding MaxDropDownHeight}" SnapsToDevicePixels="True" HorizontalScrollBarVisibility="{TemplateBinding ScrollViewer.HorizontalScrollBarVisibility}" VerticalScrollBarVisibility="{TemplateBinding ScrollViewer.VerticalScrollBarVisibility}" TextElement.FontSize="{TemplateBinding FontSize}" TextElement.FontWeight="{TemplateBinding FontWeight}" TextElement.Foreground="{TemplateBinding Foreground}">
-              <StackPanel IsItemsHost="True" KeyboardNavigation.DirectionalNavigation="Contained" />
+              <ItemsPresenter KeyboardNavigation.DirectionalNavigation="Contained" />
             </ScrollViewer>
           </Grid>
           <Border.Effect>
diff --git a/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.Light.xaml b/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.Light.xaml
index 0128462f289..5946912d270 100644
--- a/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.Light.xaml
+++ b/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.Light.xaml
@@ -1580,7 +1580,7 @@
           </Border.RenderTransform>
           <Grid>
             <ScrollViewer MaxHeight="{TemplateBinding MaxDropDownHeight}" SnapsToDevicePixels="True" HorizontalScrollBarVisibility="{TemplateBinding ScrollViewer.HorizontalScrollBarVisibility}" VerticalScrollBarVisibility="{TemplateBinding ScrollViewer.VerticalScrollBarVisibility}" TextElement.FontSize="{TemplateBinding FontSize}" TextElement.FontWeight="{TemplateBinding FontWeight}" TextElement.Foreground="{TemplateBinding Foreground}">
-              <StackPanel IsItemsHost="True" KeyboardNavigation.DirectionalNavigation="Contained" />
+              <ItemsPresenter KeyboardNavigation.DirectionalNavigation="Contained" />
             </ScrollViewer>
           </Grid>
           <Border.Effect>
@@ -1677,7 +1677,7 @@
           </Border.RenderTransform>
           <Grid>
             <ScrollViewer MaxHeight="{TemplateBinding MaxDropDownHeight}" SnapsToDevicePixels="True" HorizontalScrollBarVisibility="{TemplateBinding ScrollViewer.HorizontalScrollBarVisibility}" VerticalScrollBarVisibility="{TemplateBinding ScrollViewer.VerticalScrollBarVisibility}" TextElement.FontSize="{TemplateBinding FontSize}" TextElement.FontWeight="{TemplateBinding FontWeight}" TextElement.Foreground="{TemplateBinding Foreground}">
-              <StackPanel IsItemsHost="True" KeyboardNavigation.DirectionalNavigation="Contained" />
+              <ItemsPresenter KeyboardNavigation.DirectionalNavigation="Contained" />
             </ScrollViewer>
           </Grid>
           <Border.Effect>
diff --git a/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.xaml b/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.xaml
index a1906afee7f..15b7e284a0f 100644
--- a/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.xaml
+++ b/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Themes/Fluent.xaml
@@ -792,7 +792,7 @@
           </Border.RenderTransform>
           <Grid>
             <ScrollViewer MaxHeight="{TemplateBinding MaxDropDownHeight}" SnapsToDevicePixels="True" HorizontalScrollBarVisibility="{TemplateBinding ScrollViewer.HorizontalScrollBarVisibility}" VerticalScrollBarVisibility="{TemplateBinding ScrollViewer.VerticalScrollBarVisibility}" TextElement.FontSize="{TemplateBinding FontSize}" TextElement.FontWeight="{TemplateBinding FontWeight}" TextElement.Foreground="{TemplateBinding Foreground}">
-              <StackPanel IsItemsHost="True" KeyboardNavigation.DirectionalNavigation="Contained" />
+              <ItemsPresenter KeyboardNavigation.DirectionalNavigation="Contained" />
             </ScrollViewer>
           </Grid>
           <Border.Effect>
@@ -889,7 +889,7 @@
           </Border.RenderTransform>
           <Grid>
             <ScrollViewer MaxHeight="{TemplateBinding MaxDropDownHeight}" SnapsToDevicePixels="True" HorizontalScrollBarVisibility="{TemplateBinding ScrollViewer.HorizontalScrollBarVisibility}" VerticalScrollBarVisibility="{TemplateBinding ScrollViewer.VerticalScrollBarVisibility}" TextElement.FontSize="{TemplateBinding FontSize}" TextElement.FontWeight="{TemplateBinding FontWeight}" TextElement.Foreground="{TemplateBinding Foreground}">
-              <StackPanel IsItemsHost="True" KeyboardNavigation.DirectionalNavigation="Contained" />
+              <ItemsPresenter KeyboardNavigation.DirectionalNavigation="Contained" />
             </ScrollViewer>
           </Grid>
           <Border.Effect>