IOS横屏事件

[[UIDevice currentDevice] beginGeneratingDeviceOrientationNotifications];
   [[NSNotificationCenter defaultCenter] addObserver:self
     
                                             selector:@selector(deviceOrientationDidChange:)
     
                                                 name:UIDeviceOrientationDidChangeNotification
     
                                               object:nil];

-(void)deviceOrientationDidChange:(NSObject*)sender{
    UIDevice* device = [sender valueForKey:@"object"];
    NSLog(@"%d",device.orientation);
    
}