UIImageView 内部的 UIImage 不适合

Question

我从 API 收到高分辨率图像，我需要缩放以适应我的收藏视图单元格。 我在 UIImageView init 中使用 scaleToFit 但图像仍保持原始比例，此外，如果我在某个时刻开始滚动，它们将变为全尺寸

细胞：

final class SnapCarouselCellImpl: UICollectionViewCell, SnapCarouselCell{
    var imageView: UIImageView = {
        let imageView = UIImageView()
        imageView.contentMode = .scaleToFill
        imageView.translatesAutoresizingMaskIntoConstraints = false
        return imageView
    }()
    
    override init(frame: CGRect) {
        super.init(frame: frame)
        addSubview(imageView)
        imageView.topAnchor.constraint(equalTo: contentView.topAnchor).isActive = true
        imageView.bottomAnchor.constraint(equalTo: contentView.bottomAnchor).isActive = true
        imageView.leftAnchor.constraint(equalTo: contentView.leftAnchor).isActive = true
        imageView.rightAnchor.constraint(equalTo: contentView.rightAnchor).isActive = true
    }

风险投资：

func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "SnapCarouselCell", for: indexPath) as! SnapCarouselCellImpl
        let item = items[indexPath.row % items.count]
        cell.imageView.image = UIImage(data: item.poster)
        return cell
    }


private func setUpCollectionView() -> UICollectionView{
        let collectionView = UICollectionView(frame: self.view.frame, collectionViewLayout: flowLayout)
        collectionView.showsHorizontalScrollIndicator = false
        collectionView.frame = CGRect(x: 0, y: 100, width: view.frame.size.width, height: cellHeight * 1.2)
        collectionView.decelerationRate = .init(rawValue: 20)
        collectionView.register(SnapCarouselCellImpl.self, forCellWithReuseIdentifier: "SnapCarouselCell")
        return collectionView
    }

流布局：

override func prepare() {
        scrollDirection = .horizontal
        minimumLineSpacing = 20
        itemSize = CGSize(width: cellWidth, height: cellHeight)
        let sideMargin = (collectionView!.bounds.width - cellWidth) / 2.0
        sectionInset = UIEdgeInsets(top: 0.0, left: sideMargin, bottom: 0.0, right: sideMargin)
    }

结果：

滚动后：

Answer 1

您没有提供足够的代码来确认这一点，但是...

您可以通过在SnapCarouselCellImpl SnapCarouselCellImpl的init中更改此行来纠正此问题：

addSubview(imageView)

至：

contentView.addSubview(imageView)