In iOS 12, when does the UICollectionView layout cells, use autolayout in nib

Question

Same code like this

collectionLayout.estimatedItemSize = CGSize(width: 50, height: 25)
collectionLayout.itemSize = UICollectionViewFlowLayoutAutomaticSize
co         


        

Answer 1

Try this

override func viewWillLayoutSubviews() {
    super.viewWillLayoutSubviews()

    DispatchQueue.main.async {
        self.collectionView.collectionViewLayout.invalidateLayout()
    }
}

Adding to viewDidAppear and viewWillAppear will of course work. But viewDidAppear will cause a glitch gor the user.