Orientation don't change in second time

Question

i have this code below, that recognize when the device change his orientation, and if the orientation are landscape left or right, he back again to portrait:

    [[UIDevice currentDevice] beginGeneratingDeviceOrientationNotifications];

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


- (void) orientationChanged:(NSNotification *)note{

    UIDevice * device = note.object;

    if(device.orientation == UIDeviceOrientationLandscapeRight){


        [[UIDevice currentDevice] setValue:
         [NSNumber numberWithInteger: UIInterfaceOrientationPortrait]
                                    forKey:@"orientation"];
    }

    if(device.orientation == UIDeviceOrientationLandscapeLeft){


        [[UIDevice currentDevice] setValue:
         [NSNumber numberWithInteger: UIInterfaceOrientationPortrait]
                                    forKey:@"orientation"];
    }

}

When I run my project and change the orientation of my device to landscape right or left, this code recognize and change the orientation to portrait, but if I rotate my device again to landscape left or right, the code don't work and my device stay in landscape mode, why? and how to solve this problem?

Answer 1

I dont know if I am correct but try to fire your notification from viewWillAppear

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

}

Answer 2

It is better practice to register the notifications in the viewWillAppear and unregister in the viewWillDisappear method. So that you will catch the notifications only if your view is presenting.

Implement like :

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

-(void)viewWillDisappear:(BOOL)animated
{
  // Removing observer for lead created notification
  [[NSNotificationCenter defaultCenter] removeObserver:self];
}

And if UIDeviceOrientationDidChangeNotification is not solving your problem, try StatusBarOrientationNotification like as follows.

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(statusBarOrientationChange:) name:UIApplicationDidChangeStatusBarOrientationNotification object:nil];

- (void)statusBarOrientationChange:(NSNotification *)note {
    UIInterfaceOrientation orientation = [note.userInfo[UIApplicationStatusBarOrientationUserInfoKey] integerValue];

    // handle changes
}

Answer 3

Instead of messing with private API and get rejected from AppStore, you should simply lock rotation for your controller using standard methods such as supportedInterfaceOrientations and shouldAutorotate.