Swift viewWillTransition not called

Question

I\'m creating a full screen image gallery using a UICollectionView. When the user rotates the device, I perform updates to the UICollectionView wit

Answer 1

This is how I fixed that:

Go to Project Target - General - Deployment Info

Tick Device Orientations the app supports

Also you need (change UIInterfaceOrientationMask.all for whatever is appropriate):

override var supportedInterfaceOrientations : UIInterfaceOrientationMask {
    get {
        return UIInterfaceOrientationMask.all;
    }
}

for ViewController.