Tells the delegate that the user has attempted to close a window or the window has received a performClose: message.
Original signature is '- (BOOL)windowShouldClose:(id)sender'
Available in Mac OS X v10.0 and later.

C# | Visual Basic | Visual C++ |
public event NSWindow..::..WindowShouldCloseEventHandler WindowShouldClose
Public Event WindowShouldClose As NSWindow..::..WindowShouldCloseEventHandler
public: event NSWindow..::..WindowShouldCloseEventHandler^ WindowShouldClose { void add (NSWindow..::..WindowShouldCloseEventHandler^ value); void remove (NSWindow..::..WindowShouldCloseEventHandler^ value); }

YES to allow sender to be closed; otherwise, NO.

- Available in Monobjc Bridge: 10.6 (For Mac OS X 10.6 and later), 10.5 (For Mac OS X 10.5 and later)