Question

I am attempting to modify a TreeView to display the TreeViewItem values above and below their child items, such that:

foo
|bar
||baz
|biz

would become

foo
|bar
||baz
| baz
|bar
|biz
 biz
foo

A trimmed representation of the current control template is provided below, provided with no guarantee that this snippet compiles:

<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/>
         <RowDefinition Height="Auto"/>
      </Grid.RowDefinitions>
      <ToggleButton x:Name="Expander"
                    IsChecked="{Binding Path=IsExpanded,
                    RelativeSource={RelativeSource TemplatedParent}}"
                    ClickMode="Press"/>
      <Border Name="Bd"
              Grid.Column="1"
              Background="{TemplateBinding Background}"
              BorderBrush="{TemplateBinding BorderBrush}"
              BorderThickness="{TemplateBinding BorderThickness}"
              Padding="{TemplateBinding Padding}">
        <ContentPresenter x:Name="PART_Header"
                          ContentSource="Header"
                          HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"/>
      </Border>
      <ItemsPresenter x:Name="ItemsHost"
                      Grid.Row="1"
                      Grid.Column="1"
                      Grid.ColumnSpan="2"/>
      <TextBlock Text="Some Binding Goes Here"
                 Grid.Row="2"
                 Grid.Column="1"
                 Grid.ColumnSpan="2"/>
    </Grid>
  </ControlTemplate>

The repeated entries would not have children, it would just be the display value. Thus far I can modify the TreeView ContainerStyle using a ControlTemplate to insert a TextBlock at the appropriate place in the visual tree. What data binding should be used in order to fetch the appropriate display value?

Answer 1

Why not use a ContentPresenter again?

<ContentPresenter ContentSource="Header"
                  HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"
                  Grid.Row="2"
                  Grid.Column="1"
                  Grid.ColumnSpan="2"/>