I am new to WPF. Like many others, I am trying to bind a ContextMenu
to an ObservableCollection
to create a dynamic context menu.
Everything works except binding the Command
property to the TheCommand
property of the MenuItemViewModel
class, that represents the menu item. The command is not fired. What am I doing wrong?
To start from the beginning, the ContextMenu
is a child of the Image
and is shown when the mouse is over the Image
.
<Image.ContextMenu >
<ContextMenu ItemsSource="{DynamicResource ContextMenu}"
where the empty ContextMenu is defined as follows:
<Window.Resources>
<local:MenuItemViewModelCollection x:Key="ContextMenu">
</local:MenuItemViewModelCollection>
<HierarchicalDataTemplate DataType="{x:Type local:MenuItemViewModel}"
ItemsSource="{Binding Path=Children}">
<HierarchicalDataTemplate.ItemContainerStyle>
<Style TargetType="MenuItem">
<Setter Property="Command"
Value="{Binding RelativeSource={RelativeSource AncestorType={x:Type ContextMenu}},
Path=DataContext.TheCommand}"/>
<!-- Value="{Binding Path=TheCommand}" /> I tried this too -->
</Style>
</HierarchicalDataTemplate.ItemContainerStyle>
</HierarchicalDataTemplate>
</Window.Resources>
The TheCommand
property is defined below:
public class MenuItemViewModel : INotifyPropertyChanged
{
//...
public ICommand TheCommand
{
//...
}
}
Did you try
Value="{TemplateBinding TheCommand}"
?Look at my answer for the following question -
Context Menu items command binding WPF using MVVM
Hope it helps!
DataContext on ContextMenus can be weird, I bet if you look in the output window in Visual Studio when debugging that there will be a binding error for TheCommand not being found. Try the following:
This will use the DataContext of the element that the ContextMenu is launched from, not the context menu itself.