CollectionViewCells不会以编程方式显示-Swift 5

Question

我想显示一个在按下按钮后随动画一起显示的collectionView。

collectionView正确显示，但其中的collectionViewCells不正确。

我已经正确设置了UICollectionViewDelegate和UICollectionViewDataSource方法，但未调用它们（已通过breakPoints测试）。

我正在做所有的事情（[以编程方式，所以我还必须将[UI]通用UICollectionViewCell的SettingCell注册到相应的cellID。

[我还认为可能会出现问题，因为我设置委托和数据源的时间太晚了，但我不这么认为，因为它们是在父类的开始时设置的。

class SettingsLauncer : NSObject, UICollectionViewDelegate, UICollectionViewDataSource{

var collectionView : UICollectionView = {
    let layout = UICollectionViewLayout()
    let cv = UICollectionView(frame: .zero, collectionViewLayout: layout)
    cv.backgroundColor = .white
    return cv
}()


let CelliD = "CelliD"


func handleMoreButton(){
            //creating and adding  View
    if let windowView = UIApplication.shared.keyWindow {

        let width = UIScreen.main.bounds.width
        let height = UIScreen.main.bounds.height
        let heightCollectionView = CGFloat(300)
        let myHeight = height - heightCollectionView

        collectionView.frame = CGRect(x: 0, y: height, width: width, height: 0)

        UIView.animate(withDuration: 0.3, delay: 0, options: .curveEaseOut, animations: {

            windowView.addSubview(self.collectionView)

            self.collectionView.frame = CGRect(x: 0, y: myHeight, width: width, height: heightCollectionView)
        }, completion: nil)
    }
}



func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
    return 3

}

func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
    let cell = collectionView.dequeueReusableCell(withReuseIdentifier: CelliD, for: indexPath)

    return cell
}



override init(){
    super.init()
    collectionView.register(SettingCell.self, forCellWithReuseIdentifier: CelliD)
    collectionView.delegate = self
    collectionView.delegate = self

}
}

Answer 1

请在您的init方法中添加这两行

    self.collectionView.delegate = self
    self.collectionView.dataSource = yourDataSource

当前您正在拥有
    collectionView.delegate = self
    collectionView.delegate = self

还使您的collectionView变得懒惰...并在其中分配委托
private lazy var collectionView : UICollectionView = {
    let layout = UICollectionViewFlowLayout()
    layout.scrollDirection = .horizontal
    let cv = UICollectionView(frame: .zero, collectionViewLayout: layout)
    cv.backgroundColor = .white
    cv.delegate = self
    cv.dataSource = yourDataSource
    cv.translatesAutoresizingMaskIntoConstraints = false
    return cv
}()