Getting parent ListBox selected index as CommandParamater from context menu item

Question

I am trying to pass a listbox's Selected Index property as a command paramater to a context menu item, I have the command binding working (thanks to Will @ ElementName Binding from MenuItem in ContextMenu) but I'm have trouble with my command paramater.

<UserControl>
    <ListBox ItemsSource="{Binding myItems}">
        <ListBox.Resources> <!-- The selected item is the item the mouse is over  -->
            <Style TargetType="ListBoxItem" BasedOn="{StaticResource {x:Type ListBoxItem}}">
                <Setter Property="HorizontalContentAlignment" Value="Stretch"/>
                <Style.Triggers>
                    <DataTrigger Binding="{Binding IsMouseOver,RelativeSource={RelativeSource Self}}" 
                     Value="True">
                        <Setter Property="IsSelected" Value="True" />
                    </DataTrigger>
                </Style.Triggers>
            </Style>
        </ListBox.Resources>

        <ListBox.ItemTemplate>
            <DataTemplate>
                <Button Content="Edit" Grid.Column="4" Grid.Row="0" Tag="{Binding DataContext, ElementName=ProductBacklog}">
                    <Button.ContextMenu>
                        <ContextMenu>
                            <MenuItem Header="Remove" 
                                Command="{Binding PlacementTarget.Tag.RemoveStoryClickCommand, RelativeSource={RelativeSource AncestorType=ContextMenu}}" 
                                CommandParameter="{Binding <!--I NEED TO BIND TO THE LISTBOX-->, Path=SelectedIndex}"/>
                        </ContextMenu>
                    </Button.ContextMenu>
                </Button>
            </DataTemplate>
        </ListBox.ItemTemplate>

    </ListBox>
</UserControl>

Rachel Rachel · Accepted Answer · 2011-11-25T15:23:14

You can set the CommandParameter="{Binding }" to pass the current data item in that row to your Command

Edit

Just noticed your command is in a ContextMenu. ContextMenus are not part of WPF's default Visual Tree, so bindings do not work the same way. To bind to the current item, use the following:

<MenuItem Header="Remove" 
          Command="{Binding PlacementTarget.Tag.RemoveStoryClickCommand, RelativeSource={RelativeSource AncestorType=ContextMenu}}" 
          CommandParameter="{Binding PlacementTarget.DataContext, 
              RelativeSource={RelativeSource FindAncestor, 
              AncestorType={x:Type ContextMenu}}}" />

This will bind to the DataContext of whatever control the ContextMenu is placed on, so in this case it will be Button.DataContext

Getting parent ListBox selected index as CommandParamater from context menu item

1 Answers