当 UIImageView 有图像时，UICollectionView 自定义单元格 UILabel 丢失

Question

我在使用自定义 UICollectionViewCell 时遇到问题。自定义单元格有一个 UILabel 和一个 UIImageView。问题是，当我将图像放在 UIImageView 上时（左截图），同一单元格中的 UILabel 消失，如下图所示。但是如果UIImageView上没有Image source，UILabel是不会丢失的。

这是 Viewcontroller 的代码，其中包含 UICollectionView

class CatTowerVeiwController: UIViewController {

    @IBOutlet weak var popCountSwitch: UISwitch!
    @IBOutlet weak var collectionView: UICollectionView!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        let switchState = UserDefaults.standard.bool(forKey: UserDataKey.popCountVisibility)
        popCountSwitch.setOn(switchState, animated: false)
        
        collectionView.register(UINib(nibName: "CatTowerCell", bundle: nil), forCellWithReuseIdentifier: "cell")
        setupFlowLayout(numberOfCells: 2.0)
    }

    
    @IBAction func doneButtonClicked(_ sender: UIButton) {

        let isLabelVisible = self.popCountSwitch.isOn
        UserDefaults.standard.set(isLabelVisible, forKey: UserDataKey.popCountVisibility)
        
        
        self.dismiss(animated: false)
    
    }
}

extension CatTowerVeiwController: UICollectionViewDataSource {
    
    func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        return 3
    }
    
    func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "cell", for: indexPath) as! CatTowerCell
        
//        cell.cellImage.image = #imageLiteral(resourceName: "popcat_closed")
        cell.cellName.text = "Popcat"
        print(cell.cellName.frame.size.height)
        print(cell.cellName.frame.size.width)

        
        return cell
    }
    

}

extension CatTowerVeiwController: UICollectionViewDelegateFlowLayout {
    
    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
        let leftAndRightPaddings: CGFloat = 45.0
        let numberOfItemsPerRow: CGFloat = 2.0
    
        let width = (collectionView.frame.width-leftAndRightPaddings)/numberOfItemsPerRow
        return CGSize(width: width, height: width)
    }
    
    
    private func setupFlowLayout(numberOfCells: CGFloat) {
        let flowLayout = UICollectionViewFlowLayout()
        flowLayout.sectionInset = UIEdgeInsets(top: 10, left: 10, bottom: 10, right: 10)

        let halfWidth = UIScreen.main.bounds.width / numberOfCells
        flowLayout.itemSize = CGSize(width: halfWidth * 0.8 , height: halfWidth * 0.8)
        flowLayout.minimumInteritemSpacing = 0
        flowLayout.minimumLineSpacing = halfWidth * 0.1
        
        self.collectionView.collectionViewLayout = flowLayout
    }
}

这是自定义单元格的代码

class CatTowerCell: UICollectionViewCell {

    @IBOutlet weak var cellImage: UIImageView!
    @IBOutlet weak var cellName: UILabel!
    
    override func awakeFromNib() {
        super.awakeFromNib()
        // Initialization code
    }
}

这就是我想要做的：

Answer 1

将图像视图的底部锚点约束固定到标签的顶部锚点。并确保没有冲突约束。

label.topAnchor.constraint(equalTo: imageview.bottomAnchor).isActive = true

Answer 2

解决方案是压缩优先级

因为UIImageView太大，UILabel的高度变成了0

我的解决方案是将 UILabel 的垂直压缩优先级设置为大于 UIImageView。

当 UIImageView 有图像时，UICollectionView 自定义单元格 UILabel 丢失

UICollectionView custom cell UILabel missing when UIImageView has image

uikit

ios

uicollectionview

uicollectionviewcell

swift