ILSpy/AvalonEdit/ICSharpCode.AvalonEdit/Search/DropDownButton.xaml

<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
	xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
	xmlns:local="clr-namespace:ICSharpCode.AvalonEdit.Search"
>
	<!-- Colors for DropDownButton and SplitButton -->
	<SolidColorBrush x:Key="{ComponentResourceKey {x:Type local:DropDownButton}, ActiveBorder}" Color="#FF0A246A"/>
	<SolidColorBrush x:Key="{ComponentResourceKey {x:Type local:DropDownButton}, ActiveBackground}" Color="#FFB6BDD2"/>
	
	<!-- Style and Template for DropDownButton -->
	<Style TargetType="{x:Type local:DropDownButton}">
		<Setter Property="TextElement.Foreground" Value = "{DynamicResource {x:Static SystemColors.ControlTextBrushKey}}" />
		<Setter Property="Control.Padding" Value="2,2,2,2"/>
		<Setter Property="Border.BorderThickness" Value="1,1,1,1"/>
		<Setter Property="Panel.Background" Value="Transparent"/>
		<Setter Property="Border.BorderBrush" Value="Transparent"/>
		<Setter Property="FrameworkElement.HorizontalAlignment" Value="Center"/>
		<Setter Property="FrameworkElement.VerticalAlignment" Value="Center"/>
		<Setter Property="Control.HorizontalContentAlignment" Value="Center"/>
		<Setter Property="Control.VerticalContentAlignment" Value="Center"/>
		<Setter Property="Template">
			<Setter.Value>
				<ControlTemplate TargetType="local:DropDownButton"
				                 xmlns:s="clr-namespace:System;assembly=mscorlib">
					<Border
						BorderThickness="{TemplateBinding Border.BorderThickness}"
						BorderBrush="{TemplateBinding Border.BorderBrush}"
						Background="{TemplateBinding Panel.Background}"
						Name="OuterBorder"
						SnapsToDevicePixels="True"
					>
						<StackPanel Orientation="Horizontal">
							<ContentPresenter
								Margin="{TemplateBinding Control.Padding}"
								Content="{TemplateBinding ContentControl.Content}"
								ContentTemplate="{TemplateBinding ContentControl.ContentTemplate}"
								ContentStringFormat="{TemplateBinding ContentControl.ContentStringFormat}"
								HorizontalAlignment="{TemplateBinding Control.HorizontalContentAlignment}"
								VerticalAlignment="{TemplateBinding Control.VerticalContentAlignment}"
								SnapsToDevicePixels="{TemplateBinding UIElement.SnapsToDevicePixels}" />
							<Path Margin="0,2,2,2"
							      Data = "M0,0 L1,0 0.5,1 z"
							      Fill = "{TemplateBinding TextElement.Foreground}"
							      Width = "7"
							      Height = "3.5"
							      Stretch = "Fill"/>
						</StackPanel>
					</Border>
					<ControlTemplate.Triggers>
						<Trigger Property="UIElement.IsMouseOver" Value="True">
							<Setter Property="Border.BorderBrush" TargetName="OuterBorder" Value="{DynamicResource {ComponentResourceKey {x:Type local:DropDownButton}, ActiveBorder}}" />
							<Setter Property="Panel.Background" TargetName="OuterBorder" Value="{DynamicResource {ComponentResourceKey {x:Type local:DropDownButton}, ActiveBackground}}"/>
						</Trigger>
						<Trigger Property="UIElement.IsKeyboardFocused" Value="True">
							<Setter Property="Border.BorderBrush" TargetName="OuterBorder" Value="{DynamicResource {ComponentResourceKey {x:Type local:DropDownButton}, ActiveBorder}}"/>
							<Setter Property="Panel.Background" TargetName="OuterBorder" Value="{DynamicResource {ComponentResourceKey {x:Type local:DropDownButton}, ActiveBackground}}"/>
						</Trigger>
						<Trigger Property="UIElement.IsEnabled" Value="False">
							<Setter Property="TextElement.Foreground" Value="{DynamicResource {x:Static SystemColors.GrayTextBrushKey}}"/>
						</Trigger>
						<Trigger Property="local:DropDownButton.IsDropDownContentOpen" Value="True">
							<Setter Property="Border.BorderBrush" TargetName="OuterBorder" Value="{DynamicResource {x:Static SystemColors.ControlDarkBrushKey}}" />
							<Setter Property="Border.BorderThickness" TargetName="OuterBorder" Value="1,1,1,0" />
							<Setter Property="Border.Padding" TargetName="OuterBorder" Value="0,0,0,1" />
							<Setter Property="Panel.Background" TargetName="OuterBorder" Value="Transparent"/>
						</Trigger>
					</ControlTemplate.Triggers>
				</ControlTemplate>
			</Setter.Value>
		</Setter>
	</Style>
</ResourceDictionary>