如何在使用两种不同类型单元格时确定集合视图的大小

import UIKit

class MyCollectionViewLayout: UICollectionViewFlowLayout {
    override func layoutAttributesForElements(in rect: CGRect) -> [UICollectionViewLayoutAttributes]? {
        let layoutAttributes = super.layoutAttributesForElements(in: rect)
        for attributes in layoutAttributes ?? [] {
            if attributes.representedElementCategory == .cell {
                let indexPath = attributes.indexPath
                let cellType = determineCellType(for: indexPath)
                let size = determineSize(for: cellType)
                attributes.size = size
            }
        }
        return layoutAttributes
    }
    
    func determineCellType(for indexPath: IndexPath) -> String {
        // 根据 indexPath 判断单元格的类型，可以根据需要自定义判断逻辑
        if indexPath.row % 2 == 0 {
            return "TypeA"
        } else {
            return "TypeB"
        }
    }
    
    func determineSize(for cellType: String) -> CGSize {
        // 根据单元格的类型返回相应的大小
        if cellType == "TypeA" {
            return CGSize(width: 100, height: 100)
        } else {
            return CGSize(width: 200, height: 200)
        }
    }
}

// 在使用集合视图时，使用自定义的布局类
let layout = MyCollectionViewLayout()
let collectionView = UICollectionView(frame: CGRect(x: 0, y: 0, width: 300, height: 300), collectionViewLayout: layout)