How to show Notification Message on Shutdown of Application WPF

How to show Notification Message on Shutdown of Application WPF

I made application in which when user will click on close button of
MainWindow whole application will shutdown. I want to show a Notification
after closing of application. How to show a toast message as application
shuts'down? Here Code is :
private void Close(object sender, EventArgs e)
{
base.OnClosed(e);
Application.Current.Shutdown();
}
Can any one answer my question? Feel Free to ask if my question is not clear!