MVVM Command binding for contextemenu of TreeView Element - wpf

Question

I need to bind a command (RelayCommand) of my ViewModel with the click event on an element of the conetxtmenu for a treeviewitem
ViewModel Command
private RelayCommand _myElementCommand;
public RelayCommand MyCommand
{
get
{
return _myElementCommand?? (_myElementCommand= new RelayCommand(
x =>
{
//LoadData();
MessageBox.Show("Clicked!");
}));
}
}
VIEW
<TreeView x:Name="tvUBR" ItemsSource="{Binding UBRList, UpdateSourceTrigger=PropertyChanged}">
<TreeView.ItemTemplate>
<HierarchicalDataTemplate ItemsSource="{Binding Children}">
<StackPanel Orientation="Horizontal">
<TextBlock VerticalAlignment="Center" Text="{ Binding Description }">
<TextBlock.Style>
<Style TargetType="TextBlock">
<Setter Property="Foreground" Value="Black" />
<Style.Triggers>
<DataTrigger Binding="{Binding IsMatch}"
Value="True">
<Setter Property="Foreground" Value="Green" />
</DataTrigger>
</Style.Triggers>
</Style>
</TextBlock.Style>
<TextBlock.ContextMenu>
<ContextMenu>
<!--<MenuItem Header="Details" Command="{Binding DropedElementCommand, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=Window}}"/>-->
<MenuItem Header="Details">
<i:Interaction.Triggers>
<!-- EventName ??? -->
<i:EventTrigger EventName="Click">
<i:InvokeCommandAction Command="{Binding Path=PlacementTarget.Tag.DataContext.MyCommand, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=Window}}"/>
</i:EventTrigger>
</i:Interaction.Triggers>
</MenuItem>
</ContextMenu>
</TextBlock.ContextMenu>
</TextBlock>
</StackPanel>
</HierarchicalDataTemplate>
</TreeView.ItemTemplate>
<i:Interaction.Triggers>
<i:EventTrigger EventName="SelectedItemChanged">
<i:InvokeCommandAction Command="{Binding SelectedUBRElementCommand}"
CommandParameter="{Binding SelectedItem, ElementName=tvUBR}" />
</i:EventTrigger>
</i:Interaction.Triggers>
<TreeView.ItemContainerStyle>
<Style TargetType="{x:Type TreeViewItem}">
<Setter Property="b:TreeViewItemBehavior.IsBroughtIntoViewWhenSelected" Value="True" />
<Setter Property="IsExpanded" Value="{Binding IsExpanded, UpdateSourceTrigger=PropertyChanged, Mode=TwoWay}" />
<Setter Property="IsSelected" Value="{Binding IsSelected, UpdateSourceTrigger=PropertyChanged, Mode=TwoWay}" />
</Style>
</TreeView.ItemContainerStyle>
</TreeView>
Any idea how to achieve this?

Answer 1

You could bind the Tag property of the TextBlock to the view model and then bind to the command using the PlacementTarget property of the ContextMenu:
<HierarchicalDataTemplate ItemsSource="{Binding Children}">
<StackPanel Orientation="Horizontal">
<TextBlock VerticalAlignment="Center" Text="{ Binding Description }">
<TextBlock.Style>
<Style TargetType="TextBlock">
<Setter Property="Tag" Value="{Binding DataContext, RelativeSource={RelativeSource AncestorType=TreeView}}" />
<Setter Property="Foreground" Value="Black" />
<Style.Triggers>
<DataTrigger Binding="{Binding IsMatch}" Value="True">
<Setter Property="Foreground" Value="Green" />
</DataTrigger>
</Style.Triggers>
</Style>
</TextBlock.Style>
<TextBlock.ContextMenu>
<ContextMenu>
<MenuItem Header="Details"
Command="{Binding PlacementTarget.Tag.MyCommand, RelativeSource={RelativeSource AncestorType=ContextMenu}}" />
</ContextMenu>
</TextBlock.ContextMenu>
</TextBlock>
</StackPanel>
</HierarchicalDataTemplate>