检测indexPath FocusUpdate

Question

如何用这段代码获得和检测集中在collectionView中的项的collectionView？

- (void)didUpdateFocusInContext:(UIFocusUpdateContext *)context withAnimationCoordinator:(UIFocusAnimationCoordinator *)coordinator
{}

Answer 1

使用didUpdateFocusInContect - UICollectionViewDelegate

func collectionView(collectionView: UICollectionView, didUpdateFocusInContext context: UICollectionViewFocusUpdateContext, withAnimationCoordinator coordinator: UIFocusAnimationCoordinator) {
     // indexPath that is going to be focused
     print(context.nextFocusedIndexPath)

     // indexPath that is going to lose focus
     print(context.previouslyFocusedIndexPath)
}