How to adjust height of UICollectionView to be the height of the content size of the UICollectionView?

Question

I would like the UICollectionView (The red one) to shrink to the height of the content size in this case UICollectionViewCells(the yellow ones) because there is a lot of emp

Answer 1

1. Subclass UICollectionView as follows
2. Delete height constraint if any
3. Turn on Intrinsic Size

-

class ContentSizedCollectionView: UICollectionView {
    override var contentSize:CGSize {
        didSet {
            invalidateIntrinsicContentSize()
        }
    }

    override var intrinsicContentSize: CGSize {
        layoutIfNeeded()            
        return CGSize(width: UIView.noIntrinsicMetric, height: collectionViewLayout.collectionViewContentSize.height)
    }
}