Windows Store Content Dialog Close programmaticaly

Close content Dialog programmaticaly Windows Universal app

The following code can be used to close the new content Dialog after a period of time.

private IAsyncOperation<ContentDialogResult> dialogTask;
    private void Button_Click(object sender, RoutedEventArgs e)
    {
       ContentDialog dlg= new ContentDialog();
        dlg.Content = new TextBlock() { Text = "This content dialog will closed in 5sec!" };
        try
        {
            dialogTask = dlg.ShowAsync();
        }
        catch (TaskCanceledException)
        {
            //this was cancelled
        }

        DispatcherTimer dt = new DispatcherTimer();
        dt.Interval = TimeSpan.FromSeconds(5);
        dt.Tick += dt_Tick;
        dt.Start();
    }

    void dt_Tick(object sender, object e)
    {
        (sender as DispatcherTimer).Stop();
        dialogTask.Cancel();
    }