title: (BOOL)windowShouldClose:(id)sender doesn't work in view that i set as contentview of mainmenu's window
body: <p>I set a NSViewController's view as contentview of mainmenu's window,now how should i use - (BOOL)windowShouldClose:(id)sender ?</p>
  
  <p>i use <code>&lt;NSWindowDelegate&gt;</code> in @interface and put <code>- (BOOL)windowShouldClose:(id)sender</code> on .m but doesn't work</p>