Invoked when a menu is about to open.
Original signature is '- (void)menuWillOpen:(NSMenu *)menu'
Available in Mac OS X v10.5 and later.
- menu (NSMenu)
- The menu that is about to open.
Assembly: Monobjc.AppKit (Module: Monobjc.AppKit)
- Available in Monobjc Bridge: 10.6 (For Mac OS X 10.6 and later), 10.5 (For Mac OS X 10.5 and later)