wpf - How to distinguish 'Window close button clicked (X)' vs. window.Close() in closing handler

Question

Is there a clever way to detect whether a window was closed by

• A user pressing the (X) button in the upper right corner of the window or
• window.Close() has been called programatically.

I would like to detect this in the window.Closing handler. I could set a flag whenever I call window.Close(), but this is not a very pretty solution.

Answer 1

I'm not sure I like this at all but it's a question that you obviously have a reason for asking. if you were to take a stack trace in the OnClosing event you could look up for the Window.Close event.

protected override void OnClosing(System.ComponentModel.CancelEventArgs e)
{
   bool wasCodeClosed = new StackTrace().GetFrames().FirstOrDefault(x => x.GetMethod() == typeof(Window).GetMethod("Close")) != null;
   if (wasCodeClosed)
   {
       // Closed with this.Close()
   }
   else
   {
       // Closed some other way.
   }

   base.OnClosing(e);
}