MVVM View event Viewmodel command binding

Question

I\'m looking for a good (read: simple) example on how to implement event aggregators with Prism. I\'ve never used Prism and I\'m also quite new to MVVM itself.

I hav

Answer 1

I didn't know PRISM's EventAggregator allowed for event->command binding.

Another option for you in this case is using a "behavior". Here's a decent overview Behaviors: http://wpftutorial.net/Behaviors.html. You can ignore the Blend part of the tutorial; the important part is that you have at least the Blend 3 SDK installed. Here's how I did this:

public class ButtonDoubleClickCommandBehavior : Behavior
{
    public ICommand DoubleClickCommand
    {
        get { return (ICommand)GetValue(DoubleClickCommandProperty); }
        set { SetValue(DoubleClickCommandProperty, value); }
    }

    public static readonly DependencyProperty DoubleClickCommandProperty =
        DependencyProperty.Register("DoubleClickCommand", typeof(ICommand), typeof(ButtonDoubleClickCommandBehavior));

    protected override void OnAttached()
    {
        this.AssociatedObject.MouseDoubleClick += AssociatedObject_MouseDoubleClick;
    }

    protected override void OnDetaching()
    {
        if (this.AssociatedObject != null)
        {
            this.AssociatedObject.MouseDoubleClick -= AssociatedObject_MouseDoubleClick;
        }
    }

    void AssociatedObject_MouseDoubleClick(object sender, MouseButtonEventArgs e)
    {
        if (DoubleClickCommand != null && DoubleClickCommand.CanExecute(null))
        {
            DoubleClickCommand.Execute(null);
        }
    }
}

You could add another dependency property to the behavior to bind a command parameter so you can execute the command with that parameter; I just used null in my example.

And my XAML: