mac下生成一个全屏的窗口

NSRectscreenRect = [[NSScreen mainScreen] frame];

CGFloat w =screenRect.size.width;

CGFloat h =screenRect.size.height;

CGRect rect=  CGRectMake(0, 0, w, h);

NSWindow*fullScreenWindow= [super initWithContentRect:screenRect styleMask:NSBorderlessWindowMaskbacking:NSBackingStoreBuffered

defer:NO screen:[NSScreenmainScreen]];

// NSStatusWindowLevel窗口显示在最前面默认值是NSNormalWindowLevel

[fullScreenWindowsetLevel: NSStatusWindowLevel ];