What is the difference between UICollectionViewCell and UICollectionReusableView?

Question

Looking through UICollectionView tutorials, I see some where UICollectionViewCell is subclassed for items, and some where UICollectionReusableView is subclassed instead. The docs don't make it very clear when you would use one over the other.

Answer 1

UICollectionViewCell

A UICollectionViewCell object presents the content for a single data item when that item is within the collection view’s visible bounds. You can use this class as-is or subclass it to add additional properties and methods. The layout and presentation of cells is managed by the collection view and its corresponding layout object.

UICollectionReusableView

The UICollectionReusableView class defines the behavior for all cells and supplementary views presented by a collection view. Reusable views are so named because the collection view places them on a reuse queue rather than deleting them when they are scrolled out of the visible bounds. Such a view can then be retrieved and repurposed for a different set of content.

So the difference is that a UICollectionViewCell presents the content for a single data item and a UICollectionReusableView class defines the behavior for all cells and supplementary views presented by a collection view.

Answer 2

Actually, Apple recommends that you use UICollectionViewCell both for cells and for supplementary views. That way, you get the useful features such as the background view. UICollectionReusableView is merely what makes these views reusable. So there is no important distinction except for the built-in superclass–subclass relationship.