Pull-to-refresh in UICollectionViewController

The answers to both (1) and (2) are yes.

Simply add a UIRefreshControl instance as a subview of .collectionView and it just works.

UIRefreshControl *refreshControl = [[UIRefreshControl alloc] init];
[refreshControl addTarget:self action:@selector(startRefresh:)
    forControlEvents:UIControlEventValueChanged];
[self.collectionView addSubview:refreshControl];

That’s it! I wish this had been mentioned in the documentation somewhere, even though sometimes a simple experiment does the trick.

EDIT: this solution won’t work if the collection is not big enough to have an active scrollbar. If you add this statement,

self.collectionView.alwaysBounceVertical = YES;

then everything works perfectly. This fix taken from another post on the same topic (referenced in a comment in the other posted answer).