Dynamically binding ContextMenu items to statically defined MenuItems

Question

My application contains a TreeView which supports a set of commands, but the commands might move around between menus, only appear on some menus and not others, be shared across multiple menus, etc.

I know the set of all commands that I support at compile time, so in theory I can define a <MenuItem> resource with an x:Key attribute for each of them in my <TreeView.Resources> section. However, for any given node that is clicked, which menu items that appear can only be determined at runtime. I can bind ContextMenu.ItemsSource to something in my application that returns a MenuItem[], but in order to build this array, I would then need to access the MenuItems that were defined statically back in the XAML file.

Am I doing this all wrong? Or is there a way to do what I want?

Answer 1

Bind your ContextMenu.ItemsSource not to a MenuItem[] but a ObservableCollection < YourMenuClass >. YourMenuClass should contain the header and other parameters you want to bind to, maybe a command. Then use a template to generate your menuitems.

   <ContextMenu ItemsSource="{Binding MenuItemList}">
            <ContextMenu.ItemTemplate>
                <DataTemplate>
                    <MenuItem Header="{Binding Path=Name}" Command="{Binding MyCommand}" />
                </DataTemplate>
            </ContextMenu.ItemTemplate>
    </ContextMenu>

Answer 2

Instead of using an Itemtemplate, provide ItemContainer style for context menu. In this way you can avoid the problem of having a Menu item inside another as mentioned in the above comment.

       `<ContextMenu.ItemContainerStyle>
            <Style TargetType="{x:Type MenuItem}">
                <Setter Property="Header" Value="{Binding Name}"/>
            </Style>
        </ContextMenu.ItemContainerStyle>`