¿Cómo cambiar el color/la opacidad del icono triangular en un TreeViewItem?

Question

Algunos de mis TreeViewItems son clicables y otros no.

Para aquellos que no se puede hacer clic, cambié el color de primer plano a gris.

Sin embargo, si dicho elemento no tiene hijos , quiero cambiar también el pequeño triangular bala a gris.

¿Cómo se puede hacer eso, algo como esto:

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

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

Answer 1

que tendrá que editar el ControlTemplate. Extraje el predeterminado para ti con Expression Blend. Usted necesita lodo rato con él hasta que consiga el efecto deseado y luego aplicarlo a sus TreeViewItems así:

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

Aquí es el estilo propio:

 <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>