Notifies the delegate that the window is about to open a sheet.
Original signature is '- (void)windowWillBeginSheet:(NSNotification *)notification'
Available in Mac OS X v10.1 and later.

C# | Visual Basic | Visual C++ |
public void WindowWillBeginSheetMessage( NSNotification notification )
Public Sub WindowWillBeginSheetMessage ( _ notification As NSNotification _ )
public: void WindowWillBeginSheetMessage( NSNotification^ notification )

- notification (NSNotification)
- A notification named NSWindowWillBeginSheetNotification.

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