Getting Device Orientation in iOS

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

deviceInfo.orientation returns an UIDeviceOrientation value which is shown as below:

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

Listening for device orientation changes in a View Controller:

- (void)viewWillAppear:(BOOL)animated
{[super viewWillAppear:animated];
    [[UIDevice currentDevice] beginGeneratingDeviceOrientationNotifications];
    [[NSNotificationCenter defaultCenter] addObserver:self
}-(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
}

To disable checking for any orientation change:

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