Highlight whole TreeViewItem line in WPF

Question

If I set TreeViewItem Background it highlights the header only. How can I highlight the whole line?

I have found a post almost solving a problem http://social.msdn.microsoft.com/Forums/en-US/wpf/thread/b04f73e2-0b10-4d97-a6da-64df2e30c21d/

But there are some problems: 1. It does not highlight the whole line 2. The tree has XP style on Vista. I whould like it to looks the same way on Vista as it was, but if user changed the theme to XP - it should be XP way. 3. So many XAML...

Any ideas, what I should look for?

Answer 1

Source of the problem when use TreeView with ItemsSource is , refered from link text, I have changed some code of TreeViewItemExtensions class:

public static class TreeViewItemExtensions
{
    public static int GetDepth(this TreeViewItem item)
    {
        while (GetSelectedTreeViewItemParent(item) != null)
        {
            var parent = GetSelectedTreeViewItemParent(item);
            if (parent != null)
                return parent.GetDepth() + 1;

            item = parent;
        }
        return 0;
 }

 public static TreeViewItem GetSelectedTreeViewItemParent(this TreeViewItem item)
 {
        DependencyObject parent = VisualTreeHelper.GetParent(item);
        while (!(parent is TreeViewItem || parent is TreeView))
        {
            parent = VisualTreeHelper.GetParent(parent);
        }

        return parent as TreeViewItem;
  }
}

Answer 2

This is by far the easiest solution. Just create a rectangle, call it Hb, and set its margine to -100px and not visible. Only set it to Visible when you've it selected or mouse over. It's a hack, but you're good for up to 5 levels of nested TreeViewItems (100 > 19*5)

     <ControlTemplate TargetType="{x:Type TreeViewItem}">
  <Grid>
   <Grid.ColumnDefinitions>
    <ColumnDefinition MinWidth="19" Width="Auto"/>
    <ColumnDefinition Width="*"/>
   </Grid.ColumnDefinitions>
   <Grid.RowDefinitions>
    <RowDefinition Height="Auto"/>
    <RowDefinition/>
   </Grid.RowDefinitions>
                        <ToggleButton x:Name="Expander" Style="{StaticResource ExpandCollapseToggleStyle}" IsChecked="{Binding IsExpanded, RelativeSource={RelativeSource TemplatedParent}}" ClickMode="Press" VerticalAlignment="Top" Panel.ZIndex="1"/>
   <Rectangle x:Name="Hb" Width="Auto" Height="Auto" Grid.ColumnSpan="2" Margin="-100,0,0,0" Panel.ZIndex="-1" Visibility="Hidden" />
                        <Border x:Name="Bd" SnapsToDevicePixels="true" BorderThickness="{TemplateBinding BorderThickness}" Padding="{TemplateBinding Padding}" Grid.Column="1" Panel.ZIndex="0">
    <ContentPresenter x:Name="PART_Header" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" ContentSource="Header" HorizontalAlignment="Stretch"/>
   </Border>
   <ItemsPresenter x:Name="ItemsHost" Grid.Column="0" Grid.Row="1" Grid.ColumnSpan="2" Margin="19,0,0,0"/>
  </Grid>

Answer 3

Used something like theseven7 to facilitate use of bendewey's code with templated TreeViewItems...

    public static int GetDepth(this TreeViewItem item)
    {
        FrameworkElement elem = item;
        var parent = VisualTreeHelper.GetParent(item);
        var count = 0;
        while (parent != null && !(parent is TreeView))
        {
            var tvi = parent as TreeViewItem;
            if (parent is TreeViewItem)
                count++;
            parent = VisualTreeHelper.GetParent(parent);
        }
        return count;
    }