更改所选UICollectionView单元的大小

您可以检查是否选择了indexPath来自sizeForItemAt.如果是,则返回不同的高度,否则返回标准高度.

override func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {

    collectionView.performBatchUpdates(nil, completion: nil)
}

func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {

    switch collectionView.indexPathsForSelectedItems?.first {
    case .some(indexPath):
        return CGSize() // your selected height
    default:
        let height = (view.frame.width) * 9 / 16
        return CGSize(width: view.frame.width, height: height + 50 + 50)
    }
}