The background view placed behind all items and supplementary views.
- macOS 10.11+
The view you assign to this property is positioned underneath all other content and sized automatically to match the enclosing clip view’s frame. The view itself does not scroll with the rest of the collection view content. The view’s layer redraw policy is also changed to
In macOS 10.12 and later, a collection view that sets both
background through all areas that are not opaquely covered by the