How to programmatically determine iPhone interface orientation?

You can get orientation by 3 ways:

1. UIInterfaceOrientation orientation = self.interfaceOrientation;
   returns UIInterfaceOrientation, current orientation of the
   interface. It is a property in UIViewController, you can access to
   this one only in UIViewController classes.

2. UIInterfaceOrientation orientation = [[UIApplication sharedApplication] statusBarOrientation];
   returns UIInterfaceOrientation, current orientation of the
   application’s status bar. You can access to that property in any
   point of your application. My experience shows that this is the most
   effective way to retrieve real interface orientation.

3. UIDeviceOrientation orientation = [[UIDevice currentDevice]
orientation]; returns UIDeviceOrientation, device orientation.
   You can access to that property in any point of your
   application. But note that UIDeviceOrientation is not always
   UIInterfaceOrientation. For example, when your device is on a plain
   table you can receive unexpected value.