Detect rotation changes in iOS

Question

I am making an iOS app that needs to do a little interface rearrangement upon rotation. I am trying to detect this by implementing - (void)orientationChanged:(NSNotification *)note, but this gives me notifications for when the device is face up or face down.

I want a way to just get notified when the interface changes orientations.

Answer 1

There are several method where you can do that, you can find them in the UIViewController class reference:

– willRotateToInterfaceOrientation:duration:
– willAnimateRotationToInterfaceOrientation:duration:
– didRotateFromInterfaceOrientation:

You could also do it in the viewWillLayoutSubviews method, but be careful with it, because it is called on the screen appearance too, and whenever you add a subview.

Edit:

Solution now deprecated, see accepted answer.

Answer 2

Since iOS 8, above methods were deprecated, and the proper way to handle and detect device rotation is:

-(void) viewWillTransitionToSize:(CGSize)size withTransitionCoordinator:(id )coordinator;

To detect device orientation, you should (according to documentation): call the statusBarOrientation method to determine the device orientation

Answer 3

Since iOS 8 this is the correct way to do it.

override func viewWillTransition(to size: CGSize, with coordinator: UIViewControllerTransitionCoordinator) {
    super.viewWillTransition(to: size, with: coordinator)

    coordinator.animate(alongsideTransition: { context in
        // This is called during the animation
    }, completion: { context in
        // This is called after the rotation is finished. Equal to deprecated `didRotate`
    })
}

Answer 4

Swift 3:

override func viewWillTransition(to size: CGSize, with coordinator: UIViewControllerTransitionCoordinator) {

}