WPF style triggers on a TreeView? - wpf

Question

I have the following treeview defined in my xaml:
<TreeView Name="PST_TreeView"
Grid.Row="0"
Grid.Column="0"
Width="Auto"
Height="Auto"
HorizontalAlignment="Stretch"
VerticalAlignment="Stretch"
ItemsSource="{Binding SitesCollection}"
ItemTemplate="{StaticResource SitesTemplate}"
Style="{StaticResource TreeViewStyleBasic}" />
With Resource bindings targeting my resources file:
<Style x:Key="TreeViewStyleBasic" TargetType="TreeView">
<Setter Property="Background" Value="Transparent" />
<Setter Property="BorderBrush" Value="{DynamicResource TitleBarButtons_BorderBrush}" />
<Setter Property="BorderThickness" Value="0 0 2 0" />
</Style>
<Style x:Key="TreeViewItemStyle_CatNodes" TargetType="{x:Type TextBlock}">
<Setter Property="Foreground" Value="Snow" />
<Setter Property="FontFamily" Value="Calibri" />
<Setter Property="FontSize" Value="16" />
<Setter Property="FontWeight" Value="Normal" />
<Setter Property="TextAlignment" Value="Left" />
</Style>
<Style x:Key="TreeViewItemStyle_ChildNodes" TargetType="{x:Type TextBlock}">
<Setter Property="Foreground" Value="Snow" />
<Setter Property="FontFamily" Value="Calibri" />
<Setter Property="FontSize" Value="14" />
<Setter Property="FontWeight" Value="Normal" />
<Setter Property="FontStyle" Value="Italic" />
<Setter Property="TextAlignment" Value="Left" />
</Style>
<DataTemplate x:Key="VolumeInfoDataTemplate">
<StackPanel Orientation="Horizontal">
<TextBlock Width="{TemplateBinding Width}"
Height="{TemplateBinding Height}"
Margin="5"
Style="{DynamicResource TreeViewItemStyle_ChildNodes}"
Text="{Binding VolumeName}" />
</StackPanel>
</DataTemplate>
<HierarchicalDataTemplate x:Key="SitesTemplate"
ItemsSource="{Binding VolumesList}"
ItemTemplate="{StaticResource VolumeInfoDataTemplate}">
<StackPanel Orientation="Horizontal">
<TextBlock Width="{TemplateBinding Width}"
Height="{TemplateBinding Height}"
Margin="5"
Style="{DynamicResource TreeViewItemStyle_CatNodes}"
Text="{Binding SiteName}" />
</StackPanel>
</HierarchicalDataTemplate>
The xaml and resource look ups above work find and as expected.
How might I employ triggers to extend my style definitions to say for example handle the 'IsSelected' event so that the selected tree node will have a slate grey border and a light grey background?
RESEARCH: Kind of thing I am going for.
UPDATE: There is no IsSelected property on the TreeView, however TreeViewItem does has one defined.

Answer 1

Try this:
<DataTemplate x:Key="VolumeInfoDataTemplate">
<StackPanel Orientation="Horizontal">
<TextBlock Width="{TemplateBinding Width}"
Height="{TemplateBinding Height}"
Margin="5"
Style="{DynamicResource TreeViewItemStyle_ChildNodes}"
Text="{Binding VolumeName}"
Name="Tb" />
</StackPanel>
<DataTemplate.Triggers>
<DataTrigger Binding="{Binding IsSelected, RelativeSource={RelativeSource AncestorType=TreeViewItem}}" Value="True">
<Setter TargetName="Tb" Property="Background" Value="LightGray"/>
</DataTrigger>
</DataTemplate.Triggers>
</DataTemplate>