如何使collectionViewLayout动态更改单元格的高度和宽度？

Question

我正试图制作具有特定布局的“收藏夹视图”，如下图所示

因此，某些单元格是两行两列，而有些单元格是一一对应

如果有人有一些教程或提示，请分享。

编辑-这是我的“自定义布局”类的代码

protocol CustomLayoutDelegate: class {
    func collectionView(_ collectionView: UICollectionView, sizeForCellAtIndexPath indexPath:IndexPath) -> CGSize
}

class CustomLayout: UICollectionViewFlowLayout {

    weak var delegate: CustomLayoutDelegate!

    override func layoutAttributesForElements(in rect: CGRect) -> [UICollectionViewLayoutAttributes]? {
        let layoutAttributes = super.layoutAttributesForElements(in: rect)
        var cnt: CGFloat = 0
        var cols: CGFloat = 0
        var rows: CGFloat = 0

        layoutAttributes?.forEach({ (attributes) in
            guard let cv = collectionView else { return }
            let indexPath = IndexPath(item: attributes.indexPath.item, section: 0)
            let cellSize = delegate.collectionView(cv, sizeForCellAtIndexPath: indexPath)

            attributes.frame = CGRect(x: cellSize.width * (cols), y: cellSize.height * rows, width: cellSize.width, height: cellSize.height)
            print(cnt, cols, rows)

            cnt += 1
            cols = cols < 2 ? (cols + 1) : 0

            if Int(cnt.truncatingRemainder(dividingBy: 3)) == 0 {
                rows += 1
            }

        })

        return layoutAttributes
    }

    override func shouldInvalidateLayout(forBoundsChange newBounds: CGRect) -> Bool {
        return true
    }

}

谢谢