监听手机当前的方向

UIDevice+Orientation

UIDevice *device = [UIDevice currentDevice];					//Get the device object
        [device beginGeneratingDeviceOrientationNotifications];			//Tell it to start monitoring the accelerometer for orientation
        NSNotificationCenter *nc = [NSNotificationCenter defaultCenter];	//Get the notification centre for the app
        [nc addObserver:self											//Add yourself as an observer
               selector:@selector(orientationChanged:)
                   name:UIDeviceOrientationDidChangeNotification
                 object:device];
                 
                 
                 
- (void)orientationChanged:(NSNotification *)note
{
    //[self setNeedsStatusBarAppearanceUpdate];
    
        CGRect screenBounds = [UIScreen mainScreen].bounds;
        
        [UIView beginAnimations:nil context:nil];
            
        self.navigationController.view.transform = CGAffineTransformIdentity;
        switch ([[UIDevice currentDevice] orientation]) {
            case UIDeviceOrientationUnknown:
            case UIDeviceOrientationPortrait:
            case UIDeviceOrientationPortraitUpsideDown:
            case UIDeviceOrientationFaceUp:
            case UIDeviceOrientationFaceDown: {   // all Protrait
                
                self.navigationController.view.bounds = screenBounds;
                break;
            }
            case UIDeviceOrientationLandscapeLeft: {
                self.navigationController.view.transform = CGAffineTransformMakeRotation(M_PI_2);
                CGRect bounds = screenBounds;
                bounds.size.width = screenBounds.size.height;
                bounds.size.height = screenBounds.size.width;
                self.navigationController.view.bounds = bounds;
                break;
            }
            case UIDeviceOrientationLandscapeRight: {
                self.navigationController.view.transform = CGAffineTransformMakeRotation(-M_PI_2);
                CGRect bounds = screenBounds;
                bounds.size.width = screenBounds.size.height;
                bounds.size.height = screenBounds.size.width;
                self.navigationController.view.bounds = bounds;
                
                break;
            }
            default: {
                break;
            }
        }
        [UIView commitAnimations];
  
}