CODEWITHSUNDEEP
c#wpfmvvmrouted-commands
Billy ONeal
Billy ONeal

Reputation: 106530

Can I bind a RoutedCommand to a Command in WPF?

I have a ViewModel of the form:

class VM : DependencyObject
{
    // This class exposes a command to data binding to delete things from the model
    public static DependencyProperty DeleteProperty = DependencyProperty.Register(/*...*/);

    public static ICommand Delete {
        get {
            return (ICommand)this.GetValue(DeleteProperty);
        }
        set {
            this.SetValue(DeleteProperty, value);
        }
    }
}

For a ListBoxItem I would like to data bind execution of ApplicationCommands.Delete to this ICommand exposed by this ViewModel. That way, when someone presses the menu item that raises ApplicationCommands.Delete, this particular delete will be chosen if focus is currently on this thing:

<!-- Elsewhere... -->
<MenuItem Text="Delete" Command="ApplicationCommands.Delete" />

<!-- Some data template with DataContext == the above DependencyObject -->
<Grid>
    <Grid.CommandBindings>
        <!--
        I want ApplicationCommands.Delete to forward to the command {Binding Delete}
        -->
        <CommandBinding Command="ApplicationCommands.Delete" 
                        ???
                        />
    </Grid.CommandBindings>
</Grid>

... but CommandBinding can only bind to event handlers; not other commands, so I can't use MVVM-style data binding to attach it. Is there some MVVM mechanism I can use here or am I forced into adding code-behind for the CommandBinding?

Upvotes: 3

Views: 1865

Answers (1)

Nikita Shrivastava
Nikita Shrivastava

Reputation: 3018

You can use this tutorial to bind ApplicationCommands.
1.Add command binding collection property in your view model:

public CommandBindingCollection CommandBindings { get; }

public YourViewModel()
{
//Create a command binding for the delete command
var deleteBinding = new CommandBinding(ApplicationCommands.Delete, DeleteExecuted, DeleteCanExecute);

//Register the binding to the class
CommandManager.RegisterClassCommandBinding(typeof(YourViewModel), DeleteBinding);

//Adds the binding to the CommandBindingCollection
CommandBindings.Add(deleteBinding);
}

  1. Create attached property as mentioned in the tutorial.

  2. Then bind attached property in your UI.

Upvotes: 4

Related Questions