swift - 每个自定义单元格和自定义高度

Question

我通过 switch 函数输出 4 个自定义单元格，现在我需要为每个单元格输出动态高度值或固定高度值。我喜欢两者，因为它们的高度始终是静态的。

我订阅了 uiСollectionviewВelegateFlowLayout 协议(protocol)并找到了如何更改所有单元格的高度

func collectionView(_ collectionView: UICollectionView,
                        layout collectionViewLayout: UICollectionViewLayout,
                        sizeForItemAt indexPath: IndexPath) -> CGSize {
        let size = CGSize(width: 357, height: 600)
        return size

我使用函数覆盖单个单元格的高度

cell.frame = CGRect(cell.frame.origin.x, cell.frame.origin.y, width: 100.0, height: 100.0)

但它不起作用，“表达式类型‘@lvalue CGRect’在没有更多上下文的情况下不明确”

遇到这种情况我该怎么办？使用什么功能？

完整代码如下

// main protocols UICollectionView
extension ViewController: UICollectionViewDelegate, UICollectionViewDataSource, UICollectionViewDelegateFlowLayout {

    // width and height for cell in collectionView
    func collectionView(_ collectionView: UICollectionView,
                        layout collectionViewLayout: UICollectionViewLayout,
                        sizeForItemAt indexPath: IndexPath) -> CGSize {
        let size = CGSize(width: 357, height: 600)
        return size
    }


    //margins for cell in collectionView
    func collectionView(_ collectionView: UICollectionView, layout
        collectionViewLayout: UICollectionViewLayout,
                        minimumLineSpacingForSectionAt section: Int) -> CGFloat {
        return 40.0
    }

    func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        return 4
    }

    func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {


            var cell: UICollectionViewCell!

            switch indexPath.row {
            case 1:
                cell = collectionView.dequeueReusableCell(withReuseIdentifier: "secondCell", for: indexPath)
                    as? secondCollectionViewCell
                cell.frame = CGRect(cell.frame.origin.x, cell.frame.origin.y, width: 100.0, height: 100.0)

            case 2:
                cell = collectionView.dequeueReusableCell(withReuseIdentifier: "thirdCell", for: indexPath)
                    as? cellThirdCollectionViewCell

            case 3:
                cell = collectionView.dequeueReusableCell(withReuseIdentifier: "fourthCell", for: indexPath)
                    as? fourthCollectionViewCell

            default:
                cell = collectionView.dequeueReusableCell(withReuseIdentifier: "imageCell", for: indexPath)
                    as? imageModelCollectionViewCell
            }
            return cell
        }
    }

Answer 1

extension ViewController : UICollectionViewDelegateFlowLayout {
    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
        switch indexPath.row {
        case 1:
            return CGSize(width: 100, height: 200)
        case 2:
            return CGSize(width: 100, height: 300)
        case 3:
            return CGSize(width: 100, height: 400)
        default:
            return CGSize(width: 100, height: 100)
        }
    }
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {

        var cell: UICollectionViewCell!

        switch indexPath.row {
        case 1:
            cell = collectionView.dequeueReusableCell(withReuseIdentifier: "firstCell", for: indexPath)
                as? firstCollectionViewCell


        case 2:
            cell = collectionView.dequeueReusableCell(withReuseIdentifier: "secondCell", for: indexPath)
                as? secondCollectionViewCell

        case 3:
            cell = collectionView.dequeueReusableCell(withReuseIdentifier: "thirdCell", for: indexPath)
                as? thirdCollectionViewCell

        default:
            cell = collectionView.dequeueReusableCell(withReuseIdentifier: "imageCell", for: indexPath)
                as? imageModelCollectionViewCell
        }
        return cell
    }
}

彻底解决问题不要忘记添加

override func viewDidLoad() {
    super.viewDidLoad()
    collectionView.delegate = self
}

附注如果您收到“collectionView.delegate = self”错误，可能是因为您在 viewController 而不是 collectionViewController

中工作

需要添加IBOutlet