我想在崩溃和解体时更改扩展器的切换器。 这意味着，我想放置一个图像。 是否有更简单的方法在XAML中执行此操作而不是构建ypur自己的扩展器模板？
答案 0 :(得分：7)
只需编辑Blend中的现有模板，即创建现有模板的完整副本，然后根据需要设置样式。一旦你有完整的样式模板（我之前已经完成），应该非常简单。
这是扩展器的完整默认模板：
<SolidColorBrush x:Key="Expander.MouseOver.Circle.Stroke" Color="#FF5593FF"/>
<SolidColorBrush x:Key="Expander.MouseOver.Circle.Fill" Color="#FFF3F9FF"/>
<SolidColorBrush x:Key="Expander.MouseOver.Arrow.Stroke" Color="#FF000000"/>
<SolidColorBrush x:Key="Expander.Pressed.Circle.Stroke" Color="#FF3C77DD"/>
<SolidColorBrush x:Key="Expander.Pressed.Circle.Fill" Color="#FFD9ECFF"/>
<SolidColorBrush x:Key="Expander.Pressed.Arrow.Stroke" Color="#FF000000"/>
<SolidColorBrush x:Key="Expander.Disabled.Circle.Stroke" Color="#FFBCBCBC"/>
<SolidColorBrush x:Key="Expander.Disabled.Circle.Fill" Color="#FFE6E6E6"/>
<SolidColorBrush x:Key="Expander.Disabled.Arrow.Stroke" Color="#FF707070"/>
<SolidColorBrush x:Key="Expander.Static.Circle.Fill" Color="#FFFFFFFF"/>
<SolidColorBrush x:Key="Expander.Static.Circle.Stroke" Color="#FF333333"/>
<SolidColorBrush x:Key="Expander.Static.Arrow.Stroke" Color="#FF333333"/>
<Style x:Key="ExpanderRightHeaderStyle" TargetType="{x:Type ToggleButton}">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type ToggleButton}">
<Border Padding="{TemplateBinding Padding}">
<Grid Background="Transparent" SnapsToDevicePixels="False">
<Grid.RowDefinitions>
<RowDefinition Height="19"/>
<RowDefinition Height="*"/>
</Grid.RowDefinitions>
<Grid>
<Grid.LayoutTransform>
<TransformGroup>
<TransformGroup.Children>
<TransformCollection>
<RotateTransform Angle="-90"/>
</TransformCollection>
</TransformGroup.Children>
</TransformGroup>
</Grid.LayoutTransform>
<Ellipse x:Name="circle" Fill="{StaticResource Expander.Static.Circle.Fill}" HorizontalAlignment="Center" Height="19" Stroke="{StaticResource Expander.Static.Circle.Stroke}" VerticalAlignment="Center" Width="19"/>
<Path x:Name="arrow" Data="M 1,1.5 L 4.5,5 L 8,1.5" HorizontalAlignment="Center" SnapsToDevicePixels="false" Stroke="{StaticResource Expander.Static.Arrow.Stroke}" StrokeThickness="2" VerticalAlignment="Center"/>
</Grid>
<ContentPresenter HorizontalAlignment="Center" Margin="0,4,0,0" Grid.Row="1" RecognizesAccessKey="True" SnapsToDevicePixels="True" VerticalAlignment="Top"/>
</Grid>
</Border>
<ControlTemplate.Triggers>
<Trigger Property="IsChecked" Value="true">
<Setter Property="Data" TargetName="arrow" Value="M 1,4.5 L 4.5,1 L 8,4.5"/>
</Trigger>
<Trigger Property="IsMouseOver" Value="true">
<Setter Property="Stroke" TargetName="circle" Value="{StaticResource Expander.MouseOver.Circle.Stroke}"/>
<Setter Property="Fill" TargetName="circle" Value="{StaticResource Expander.MouseOver.Circle.Fill}"/>
<Setter Property="Stroke" TargetName="arrow" Value="{StaticResource Expander.MouseOver.Arrow.Stroke}"/>
</Trigger>
<Trigger Property="IsPressed" Value="true">
<Setter Property="Stroke" TargetName="circle" Value="{StaticResource Expander.Pressed.Circle.Stroke}"/>
<Setter Property="StrokeThickness" TargetName="circle" Value="1.5"/>
<Setter Property="Fill" TargetName="circle" Value="{StaticResource Expander.Pressed.Circle.Fill}"/>
<Setter Property="Stroke" TargetName="arrow" Value="{StaticResource Expander.Pressed.Arrow.Stroke}"/>
</Trigger>
<Trigger Property="IsEnabled" Value="false">
<Setter Property="Stroke" TargetName="circle" Value="{StaticResource Expander.Disabled.Circle.Stroke}"/>
<Setter Property="Fill" TargetName="circle" Value="{StaticResource Expander.Disabled.Circle.Fill}"/>
<Setter Property="Stroke" TargetName="arrow" Value="{StaticResource Expander.Disabled.Arrow.Stroke}"/>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
<Style x:Key="ExpanderUpHeaderStyle" TargetType="{x:Type ToggleButton}">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type ToggleButton}">
<Border Padding="{TemplateBinding Padding}">
<Grid Background="Transparent" SnapsToDevicePixels="False">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="19"/>
<ColumnDefinition Width="*"/>
</Grid.ColumnDefinitions>
<Grid>
<Grid.LayoutTransform>
<TransformGroup>
<TransformGroup.Children>
<TransformCollection>
<RotateTransform Angle="180"/>
</TransformCollection>
</TransformGroup.Children>
</TransformGroup>
</Grid.LayoutTransform>
<Ellipse x:Name="circle" Fill="{StaticResource Expander.Static.Circle.Fill}" HorizontalAlignment="Center" Height="19" Stroke="{StaticResource Expander.Static.Circle.Stroke}" VerticalAlignment="Center" Width="19"/>
<Path x:Name="arrow" Data="M 1,1.5 L 4.5,5 L 8,1.5" HorizontalAlignment="Center" SnapsToDevicePixels="false" Stroke="{StaticResource Expander.Static.Arrow.Stroke}" StrokeThickness="2" VerticalAlignment="Center"/>
</Grid>
<ContentPresenter Grid.Column="1" HorizontalAlignment="Left" Margin="4,0,0,0" RecognizesAccessKey="True" SnapsToDevicePixels="True" VerticalAlignment="Center"/>
</Grid>
</Border>
<ControlTemplate.Triggers>
<Trigger Property="IsChecked" Value="true">
<Setter Property="Data" TargetName="arrow" Value="M 1,4.5 L 4.5,1 L 8,4.5"/>
</Trigger>
<Trigger Property="IsMouseOver" Value="true">
<Setter Property="Stroke" TargetName="circle" Value="{StaticResource Expander.MouseOver.Circle.Stroke}"/>
<Setter Property="Fill" TargetName="circle" Value="{StaticResource Expander.MouseOver.Circle.Fill}"/>
<Setter Property="Stroke" TargetName="arrow" Value="{StaticResource Expander.MouseOver.Arrow.Stroke}"/>
</Trigger>
<Trigger Property="IsPressed" Value="true">
<Setter Property="Stroke" TargetName="circle" Value="{StaticResource Expander.Pressed.Circle.Stroke}"/>
<Setter Property="StrokeThickness" TargetName="circle" Value="1.5"/>
<Setter Property="Fill" TargetName="circle" Value="{StaticResource Expander.Pressed.Circle.Fill}"/>
<Setter Property="Stroke" TargetName="arrow" Value="{StaticResource Expander.Pressed.Arrow.Stroke}"/>
</Trigger>
<Trigger Property="IsEnabled" Value="false">
<Setter Property="Stroke" TargetName="circle" Value="{StaticResource Expander.Disabled.Circle.Stroke}"/>
<Setter Property="Fill" TargetName="circle" Value="{StaticResource Expander.Disabled.Circle.Fill}"/>
<Setter Property="Stroke" TargetName="arrow" Value="{StaticResource Expander.Disabled.Arrow.Stroke}"/>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
<Style x:Key="ExpanderLeftHeaderStyle" TargetType="{x:Type ToggleButton}">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type ToggleButton}">
<Border Padding="{TemplateBinding Padding}">
<Grid Background="Transparent" SnapsToDevicePixels="False">
<Grid.RowDefinitions>
<RowDefinition Height="19"/>
<RowDefinition Height="*"/>
</Grid.RowDefinitions>
<Grid>
<Grid.LayoutTransform>
<TransformGroup>
<TransformGroup.Children>
<TransformCollection>
<RotateTransform Angle="90"/>
</TransformCollection>
</TransformGroup.Children>
</TransformGroup>
</Grid.LayoutTransform>
<Ellipse x:Name="circle" Fill="{StaticResource Expander.Static.Circle.Fill}" HorizontalAlignment="Center" Height="19" Stroke="{StaticResource Expander.Static.Circle.Stroke}" VerticalAlignment="Center" Width="19"/>
<Path x:Name="arrow" Data="M 1,1.5 L 4.5,5 L 8,1.5" HorizontalAlignment="Center" SnapsToDevicePixels="false" Stroke="{StaticResource Expander.Static.Arrow.Stroke}" StrokeThickness="2" VerticalAlignment="Center"/>
</Grid>
<ContentPresenter HorizontalAlignment="Center" Margin="0,4,0,0" Grid.Row="1" RecognizesAccessKey="True" SnapsToDevicePixels="True" VerticalAlignment="Top"/>
</Grid>
</Border>
<ControlTemplate.Triggers>
<Trigger Property="IsChecked" Value="true">
<Setter Property="Data" TargetName="arrow" Value="M 1,4.5 L 4.5,1 L 8,4.5"/>
</Trigger>
<Trigger Property="IsMouseOver" Value="true">
<Setter Property="Stroke" TargetName="circle" Value="{StaticResource Expander.MouseOver.Circle.Stroke}"/>
<Setter Property="Fill" TargetName="circle" Value="{StaticResource Expander.MouseOver.Circle.Fill}"/>
<Setter Property="Stroke" TargetName="arrow" Value="{StaticResource Expander.MouseOver.Arrow.Stroke}"/>
</Trigger>
<Trigger Property="IsPressed" Value="true">
<Setter Property="Stroke" TargetName="circle" Value="{StaticResource Expander.Pressed.Circle.Stroke}"/>
<Setter Property="StrokeThickness" TargetName="circle" Value="1.5"/>
<Setter Property="Fill" TargetName="circle" Value="{StaticResource Expander.Pressed.Circle.Fill}"/>
<Setter Property="Stroke" TargetName="arrow" Value="{StaticResource Expander.Pressed.Arrow.Stroke}"/>
</Trigger>
<Trigger Property="IsEnabled" Value="false">
<Setter Property="Stroke" TargetName="circle" Value="{StaticResource Expander.Disabled.Circle.Stroke}"/>
<Setter Property="Fill" TargetName="circle" Value="{StaticResource Expander.Disabled.Circle.Fill}"/>
<Setter Property="Stroke" TargetName="arrow" Value="{StaticResource Expander.Disabled.Arrow.Stroke}"/>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
<Style x:Key="ExpanderHeaderFocusVisual">
<Setter Property="Control.Template">
<Setter.Value>
<ControlTemplate>
<Border>
<Rectangle Margin="0" SnapsToDevicePixels="true" Stroke="Black" StrokeThickness="1" StrokeDashArray="1 2"/>
</Border>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
<Style x:Key="ExpanderDownHeaderStyle" TargetType="{x:Type ToggleButton}">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type ToggleButton}">
<Border Padding="{TemplateBinding Padding}">
<Grid Background="Transparent" SnapsToDevicePixels="False">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="19"/>
<ColumnDefinition Width="*"/>
</Grid.ColumnDefinitions>
<Ellipse x:Name="circle" Fill="{StaticResource Expander.Static.Circle.Fill}" HorizontalAlignment="Center" Height="19" Stroke="{StaticResource Expander.Static.Circle.Stroke}" VerticalAlignment="Center" Width="19"/>
<Path x:Name="arrow" Data="M 1,1.5 L 4.5,5 L 8,1.5" HorizontalAlignment="Center" SnapsToDevicePixels="false" Stroke="{StaticResource Expander.Static.Arrow.Stroke}" StrokeThickness="2" VerticalAlignment="Center"/>
<ContentPresenter Grid.Column="1" HorizontalAlignment="Left" Margin="4,0,0,0" RecognizesAccessKey="True" SnapsToDevicePixels="True" VerticalAlignment="Center"/>
</Grid>
</Border>
<ControlTemplate.Triggers>
<Trigger Property="IsChecked" Value="true">
<Setter Property="Data" TargetName="arrow" Value="M 1,4.5 L 4.5,1 L 8,4.5"/>
</Trigger>
<Trigger Property="IsMouseOver" Value="true">
<Setter Property="Stroke" TargetName="circle" Value="{StaticResource Expander.MouseOver.Circle.Stroke}"/>
<Setter Property="Fill" TargetName="circle" Value="{StaticResource Expander.MouseOver.Circle.Fill}"/>
<Setter Property="Stroke" TargetName="arrow" Value="{StaticResource Expander.MouseOver.Arrow.Stroke}"/>
</Trigger>
<Trigger Property="IsPressed" Value="true">
<Setter Property="Stroke" TargetName="circle" Value="{StaticResource Expander.Pressed.Circle.Stroke}"/>
<Setter Property="StrokeThickness" TargetName="circle" Value="1.5"/>
<Setter Property="Fill" TargetName="circle" Value="{StaticResource Expander.Pressed.Circle.Fill}"/>
<Setter Property="Stroke" TargetName="arrow" Value="{StaticResource Expander.Pressed.Arrow.Stroke}"/>
</Trigger>
<Trigger Property="IsEnabled" Value="false">
<Setter Property="Stroke" TargetName="circle" Value="{StaticResource Expander.Disabled.Circle.Stroke}"/>
<Setter Property="Fill" TargetName="circle" Value="{StaticResource Expander.Disabled.Circle.Fill}"/>
<Setter Property="Stroke" TargetName="arrow" Value="{StaticResource Expander.Disabled.Arrow.Stroke}"/>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
<Style TargetType="{x:Type Expander}">
<Setter Property="Foreground" Value="{DynamicResource {x:Static SystemColors.ControlTextBrushKey}}"/>
<Setter Property="Background" Value="Transparent"/>
<Setter Property="HorizontalContentAlignment" Value="Stretch"/>
<Setter Property="VerticalContentAlignment" Value="Stretch"/>
<Setter Property="BorderBrush" Value="Transparent"/>
<Setter Property="BorderThickness" Value="1"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type Expander}">
<Border BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" Background="{TemplateBinding Background}" CornerRadius="3" SnapsToDevicePixels="true">
<DockPanel>
<ToggleButton x:Name="HeaderSite" ContentTemplate="{TemplateBinding HeaderTemplate}" ContentTemplateSelector="{TemplateBinding HeaderTemplateSelector}" Content="{TemplateBinding Header}" DockPanel.Dock="Top" Foreground="{TemplateBinding Foreground}" FontWeight="{TemplateBinding FontWeight}" FocusVisualStyle="{StaticResource ExpanderHeaderFocusVisual}" FontStyle="{TemplateBinding FontStyle}" FontStretch="{TemplateBinding FontStretch}" FontSize="{TemplateBinding FontSize}" FontFamily="{TemplateBinding FontFamily}" HorizontalContentAlignment="{TemplateBinding HorizontalContentAlignment}" IsChecked="{Binding IsExpanded, Mode=TwoWay, RelativeSource={RelativeSource TemplatedParent}}" Margin="1" MinWidth="0" MinHeight="0" Padding="{TemplateBinding Padding}" Style="{StaticResource ExpanderDownHeaderStyle}" VerticalContentAlignment="{TemplateBinding VerticalContentAlignment}"/>
<ContentPresenter x:Name="ExpandSite" DockPanel.Dock="Bottom" Focusable="false" HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" Margin="{TemplateBinding Padding}" Visibility="Collapsed" VerticalAlignment="{TemplateBinding VerticalContentAlignment}"/>
</DockPanel>
</Border>
<ControlTemplate.Triggers>
<Trigger Property="IsExpanded" Value="true">
<Setter Property="Visibility" TargetName="ExpandSite" Value="Visible"/>
</Trigger>
<Trigger Property="ExpandDirection" Value="Right">
<Setter Property="DockPanel.Dock" TargetName="ExpandSite" Value="Right"/>
<Setter Property="DockPanel.Dock" TargetName="HeaderSite" Value="Left"/>
<Setter Property="Style" TargetName="HeaderSite" Value="{StaticResource ExpanderRightHeaderStyle}"/>
</Trigger>
<Trigger Property="ExpandDirection" Value="Up">
<Setter Property="DockPanel.Dock" TargetName="ExpandSite" Value="Top"/>
<Setter Property="DockPanel.Dock" TargetName="HeaderSite" Value="Bottom"/>
<Setter Property="Style" TargetName="HeaderSite" Value="{StaticResource ExpanderUpHeaderStyle}"/>
</Trigger>
<Trigger Property="ExpandDirection" Value="Left">
<Setter Property="DockPanel.Dock" TargetName="ExpandSite" Value="Left"/>
<Setter Property="DockPanel.Dock" TargetName="HeaderSite" Value="Right"/>
<Setter Property="Style" TargetName="HeaderSite" Value="{StaticResource ExpanderLeftHeaderStyle}"/>
</Trigger>
<Trigger Property="IsEnabled" Value="false">
<Setter Property="Foreground" Value="{DynamicResource {x:Static SystemColors.GrayTextBrushKey}}"/>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
主模板使用的每种样式都定义了一个椭圆和一条路径，您可以将其更改为使用具有可绑定源的图像或您想要执行的任何操作。