Wie ändert man die Farbe/Deckkraft des dreieckigen Symbols in einem TreeViewItem?

Question

Einige meiner TreeViewItems sind anklickbar und einige sind nicht.

Für diejenigen, die nicht anklickbar sind, änderte ich die Vordergrund Farbe auf grau.

Wenn jedoch das Element hat Kinder, mag ich auch die kleine dreieckige Kugel ändern bis grau.

Wie kann ich das tun, so etwas wie dieses:

//PSEUDO-CODE: 
<TreeViewItem IconBulletEnabled="False" IconBulletColor="#aaa" Header="Part 1"/> 

alt text http://i36.tinypic.com/33mpo5x.png

Answer 1

Sie das Control bearbeiten müssen. Ich habe den Standard für Sie mit Expression Blend extrahiert. Sie müssen damit vertrödeln, bis Sie den gewünschten Effekt erreichen und dann wenden Sie es auf Ihrem TreeViewItems wie folgt aus:

<TreeViewItem Header="Word 1" ItemContainerStyle="{DynamicResource TreeViewItemStyle1}"/> 

Hier ist der Stil selbst:

 <Style x:Key="TreeViewItemFocusVisual"> 
      <Setter Property="Control.Template"> 
       <Setter.Value> 
        <ControlTemplate> 
         <Rectangle/> 
        </ControlTemplate> 
       </Setter.Value> 
      </Setter> 
     </Style> 
     <PathGeometry x:Key="TreeArrow" Figures="M0,0 L0,6 L6,0 z"/> 
     <Style x:Key="ExpandCollapseToggleStyle" TargetType="{x:Type ToggleButton}"> 
      <Setter Property="Focusable" Value="False"/> 
      <Setter Property="Width" Value="16"/> 
      <Setter Property="Height" Value="16"/> 
      <Setter Property="Template"> 
       <Setter.Value> 
        <ControlTemplate TargetType="{x:Type ToggleButton}"> 
         <Border Width="16" Height="16" Background="Transparent" Padding="5,5,5,5"> 
          <Path x:Name="ExpandPath" Fill="Transparent" Stroke="#FF989898" Data="{StaticResource TreeArrow}"> 
           <Path.RenderTransform> 
            <RotateTransform Angle="135" CenterX="3" CenterY="3"/> 
           </Path.RenderTransform> 
          </Path> 
         </Border> 
         <ControlTemplate.Triggers> 
          <Trigger Property="IsMouseOver" Value="True"> 
           <Setter Property="Stroke" TargetName="ExpandPath" Value="#FF1BBBFA"/> 
           <Setter Property="Fill" TargetName="ExpandPath" Value="Transparent"/> 
          </Trigger> 
          <Trigger Property="IsChecked" Value="True"> 
           <Setter Property="RenderTransform" TargetName="ExpandPath"> 
            <Setter.Value> 
             <RotateTransform Angle="180" CenterX="3" CenterY="3"/> 
            </Setter.Value> 
           </Setter> 
           <Setter Property="Fill" TargetName="ExpandPath" Value="#FF595959"/> 
           <Setter Property="Stroke" TargetName="ExpandPath" Value="#FF262626"/> 
          </Trigger> 
         </ControlTemplate.Triggers> 
        </ControlTemplate> 
       </Setter.Value> 
      </Setter> 
     </Style> 
     <Style x:Key="TreeViewItemStyle1" TargetType="{x:Type TreeViewItem}"> 
      <Setter Property="Background" Value="Transparent"/> 
      <Setter Property="HorizontalContentAlignment" Value="{Binding HorizontalContentAlignment, RelativeSource={RelativeSource AncestorType={x:Type ItemsControl}}}"/> 
      <Setter Property="VerticalContentAlignment" Value="{Binding VerticalContentAlignment, RelativeSource={RelativeSource AncestorType={x:Type ItemsControl}}}"/> 
      <Setter Property="Padding" Value="1,0,0,0"/> 
      <Setter Property="Foreground" Value="{DynamicResource {x:Static SystemColors.ControlTextBrushKey}}"/> 
      <Setter Property="FocusVisualStyle" Value="{StaticResource TreeViewItemFocusVisual}"/> 
      <Setter Property="Template"> 
       <Setter.Value> 
        <ControlTemplate TargetType="{x:Type TreeViewItem}"> 
         <Grid> 
          <Grid.ColumnDefinitions> 
           <ColumnDefinition MinWidth="19" Width="Auto"/> 
           <ColumnDefinition Width="Auto"/> 
           <ColumnDefinition Width="*"/> 
          </Grid.ColumnDefinitions> 
          <Grid.RowDefinitions> 
           <RowDefinition Height="Auto"/> 
           <RowDefinition/> 
          </Grid.RowDefinitions> 
          <ToggleButton x:Name="Expander" Style="{StaticResource ExpandCollapseToggleStyle}" ClickMode="Press" IsChecked="{Binding IsExpanded, RelativeSource={RelativeSource TemplatedParent}}"/> 
          <Border x:Name="Bd" SnapsToDevicePixels="true" Background="{TemplateBinding Background}" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" Padding="{TemplateBinding Padding}" Grid.Column="1"> 
           <ContentPresenter x:Name="PART_Header" HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" ContentSource="Header"/> 
          </Border> 
          <ItemsPresenter x:Name="ItemsHost" Grid.Column="1" Grid.ColumnSpan="2" Grid.Row="1"/> 
         </Grid> 
         <ControlTemplate.Triggers> 
          <Trigger Property="IsExpanded" Value="false"> 
           <Setter Property="Visibility" TargetName="ItemsHost" Value="Collapsed"/> 
          </Trigger> 
          <Trigger Property="HasItems" Value="false"> 
           <Setter Property="Visibility" TargetName="Expander" Value="Hidden"/> 
          </Trigger> 
          <Trigger Property="IsSelected" Value="true"> 
           <Setter Property="Background" TargetName="Bd" Value="{DynamicResource {x:Static SystemColors.HighlightBrushKey}}"/> 
           <Setter Property="Foreground" Value="{DynamicResource {x:Static SystemColors.HighlightTextBrushKey}}"/> 
          </Trigger> 
          <MultiTrigger> 
           <MultiTrigger.Conditions> 
            <Condition Property="IsSelected" Value="true"/> 
            <Condition Property="IsSelectionActive" Value="false"/> 
           </MultiTrigger.Conditions> 
           <Setter Property="Background" TargetName="Bd" Value="{DynamicResource {x:Static SystemColors.ControlBrushKey}}"/> 
           <Setter Property="Foreground" Value="{DynamicResource {x:Static SystemColors.ControlTextBrushKey}}"/> 
          </MultiTrigger> 
          <Trigger Property="IsEnabled" Value="false"> 
           <Setter Property="Foreground" Value="{DynamicResource {x:Static SystemColors.GrayTextBrushKey}}"/> 
          </Trigger> 
         </ControlTemplate.Triggers> 
        </ControlTemplate> 
       </Setter.Value> 
      </Setter> 
      <Style.Triggers> 
       <Trigger Property="VirtualizingStackPanel.IsVirtualizing" Value="true"> 
        <Setter Property="ItemsPanel"> 
         <Setter.Value> 
          <ItemsPanelTemplate> 
           <VirtualizingStackPanel/> 
          </ItemsPanelTemplate> 
         </Setter.Value> 
        </Setter> 
       </Trigger> 
      </Style.Triggers> 
     </Style>