获得设备方向

UIDevice *deviceInfo = [UIDevice currentDevice];
int d = deviceInfo.orientation;

deviceInfo.orientation 返回一个 UIDeviceOrientation 值，如下所示：

UIDeviceOrientationUnknown 0
UIDeviceOrientationPortrait 1
UIDeviceOrientationPortraitUpsideDown 2
UIDeviceOrientationLandscapeLeft 3
UIDeviceOrientationLandscapeRight 4
UIDeviceOrientationFaceUp 5
UIDeviceOrientationFaceDown 6

在视图控制器中侦听设备方向更改：

- (void)viewWillAppear:(BOOL)animated
{
    [super viewWillAppear:animated];
    [[UIDevice currentDevice] beginGeneratingDeviceOrientationNotifications];
    [[NSNotificationCenter defaultCenter] addObserver:self 
                                             selector:@selector(deviceOrientationDidChange) 
                                                 name:UIDeviceOrientationDidChangeNotification
                                               object:nil];
}

-(void)deviceOrientationDidChange
{
    UIDeviceOrientation orientation = [[UIDevice currentDevice] orientation];
    if (orientation == UIDeviceOrientationPortrait || orientation == UIDeviceOrientationPortraitUpsideDown) {
         [self changedToPortrait];
    } else if (orientation == UIDeviceOrientationLandscapeLeft || orientation == UIDeviceOrientationLandscapeRight) {
         [self changedToLandscape];
    }

-(void)changedToPortrait
{
    // Function Body
}

-(void)changedToLandscape
{
    // Function Body
}

要禁用检查任何方向更改：

- (void)viewWillDisappear:(BOOL)animated {
    [super viewWillDisappear:animated];
    [[UIDevice currentDevice] endGeneratingDeviceOrientationNotifications];
}