My UICollectionView cells contain UILabels with multiline text. I don't know the height of the cells until the text has been set on the label.
-(CGSize)collectionView:(UICollectionView *)collectionView
layout:(UICollectionViewLayout*)collectionViewLayout
sizeForItemAtIndexPath:(NSIndexPath *)indexPath;
This was the initial method I looked at to size the cells. However, this is called BEFORE the cells are created out of the storyboard.
Is there a way to layout the collection and size the cells AFTER they have been rendered, and I know the actual size of the cell?
Best Answer
I think your are looking for the
invalidateLayout
method you can call on the.collectionViewLayout
property of your UICollectionView. This method regenerates your layout, which in your case means also calling-collectionView: layout: sizeForItemAtIndexPath:
, which is the right place to reflect your desired item size. Jirune points the right direction on how to calculate them.An example for the usage of
invalidateLayout
can be found here. Also consult the UICollectionViewLayout documentation on that method:Edit:
For storyboard collection view which contains auto layout constraints, you need to override
viewDidLayoutSubviews
method ofUIViewController
and callinvalidateLayout
collection view layout in this method.