Swift: How to refresh UICollectionView layout after rotation of the device

Question

I used UICollectionView (flowlayout) to build a simple layout. the width for each cell is set to the width of screen using self.view.frame.width

but whe

Answer 1

Also you can invalidate it in this way.

- (void)viewWillTransitionToSize:(CGSize)size withTransitionCoordinator:(id)coordinator {
    [super viewWillTransitionToSize:size withTransitionCoordinator:coordinator];

    [self.collectionView.collectionViewLayout invalidateLayout]; 
}