title: How do I show an unsaved changes dialog box before application closing?
body: <p>I have a C# Windows Forms Application</p>
  
  <p>I want to show a "There are unsaved changes. Save/Quit/Cancel" style confirmation dialog before the Application shuts down. Potentially also while prevent the Application Shutdown. How do I do that?</p>
  
  <p>Also if the application does not close, what wil happen with the Shutdown Process on a Windows 10?</p>