contentSize is not updated after reloadData is called on UICollectionView

Question

Does anyone know why contentSize is not updated immediately after reloadData is called on UICollectionView?

If you need to know the contentSize the best work around

Answer 1

In my case, I had a custom layout class that inherits UICollectionViewFlowLayout and set it only in the Interface Builder. I accidentally removed the class from the project but Xcode didn't give me any error, and the contentSize of the collection view returned always zero.

I put back the class and it started working again.