the behavior of the UICollectionViewFlowLayout is not defined, because the cell width is greater than collectionView width

Question

2015-08-18 16:07:51.523 Example[16070:269647] the behavior of the UICollectionViewFlowLayout is not defined because: 2015-08-18 16:07:51.523
Example

Answer 1

Any Changes in UIView must be done from main thread. Put your code of collectionView addition to views hierarchy into:

DispatchQueue.main.async {
    ...  
}