DialogBehavior for MahApps.Metro MessageBox

DialogBehavior.cs

    public class DialogBehavior : Behavior<MetroWindow>
    {
        public MetroWindow Window { get; set; }

        protected override void OnAttached()
        {
            base.OnAttached();
          
            Window = base.AssociatedObject;

            //Here you'd use Caliburn's EventBus or whatever...
            Messenger.Default.Register<DialogMessageAction<string>>(this, DialogMessageToken.InputDialog, DisplayInputDialog);
            Messenger.Default.Register<NotificationMessage>(this, DialogMessageToken.ErrorDialog, DisplayErrorDialog);
            Messenger.Default.Register<DialogMessageAction<string>>(this, DialogMessageToken.ProgressDialog, async action => await DisplayProgressDialog(action));
        }

        private void DisplayInputDialog(DialogMessageAction<string> m)
        {
            Window.ShowInputAsync(m.DialogTitle, m.Notification, new MetroDialogSettings{ DefaultText = m.DefaultMessage }).ContinueWith(result =>
            {
                if (result.Result == null) //user cancelled
                {
                    return;
                }

                m.Execute(result.Result);
            });
        }

        private async Task DisplayProgressDialog(DialogMessageAction<string> m)
        {
            var controller = await Window.ShowProgressAsync(m.DialogTitle, m.Notification);

            await TaskEx.Delay(5000);

            double i = 0.0;
            while (i < 6.0)
            {
                double val = ((double)(i/100.0))*20.0;
                controller.SetProgress(val);
                controller.SetMessage("Completing Task..." + (val*100) + " percent complete.");

                i += 1.0;

                await TaskEx.Delay(2000);
            }

            await controller.CloseAsync();
        }

        private void DisplayErrorDialog(NotificationMessage m)
        {
            Window.ShowMessageAsync("Error", m.Notification).ContinueWith(result => { });
        }

        protected override void OnDetaching()
        {
            Messenger.Default.Unregister(this);
        }
    }

DialogMessageAction.cs

public class DialogMessageAction<T> : NotificationMessageWithCallback
{
    public string DialogTitle { get; set; }
    public string DefaultMessage { get; set; }

    public DialogMessageAction(string notification, string dialogTitle, string defaultMessage, Action<T> callback) : base(notification, callback)
    {
        DialogTitle = dialogTitle;
        DefaultMessage = defaultMessage;
    }
}

MainWindow.xaml

<!-- Then just add this to your ModernWindow -->
<i:Interaction.Behaviors>
    <behaviors:DialogBehavior/>
</i:Interaction.Behaviors>