How can I know the orientation changed in AppDelegate

Question

The function of how the device know the changement of orientation is -(void)viewWillLayoutSubviews and -(void)viewDidLayoutSubviews But, they are just in the controllers;

Answer 1

If you are talking about the interface orientation you could observe theUIApplicationDidChangeStatusBarOrientationNotification and if you want to be notified when the device orientation changed you can observe UIDeviceOrientationDidChangeNotification