ios - UI 中显示的单元格数量小于数据计数

Question

猜猜我的 cellForItemAt 的 collectionView 函数没有正确调用。第二行和第三行计数丢失。即行计数的输出为
行=> 0
行 => 1
行=> 4
行=> 5
但我的数据计数是 6，这是正确的。否则，显示的 4 个单元格与图像和其他数据完美匹配。

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

        cell = collectionView.dequeueReusableCell(withReuseIdentifier: CELL_IDENTIFIER, for: indexPath) as? CollectionViewCell

        var row  = indexPath.row
        print ("row =>", row)
        let imageView = UIImageView()
        var imgURL: String? = nil
        if let object = (dataSource[row] as? [AnyHashable : Any])?["src"] {
            imgURL = "\(object)"
        }
        let url = URL(string: imgURL ?? "")
        cell?.cellImageView.sd_setImage(with: url, placeholderImage: UIImage(named: "placeholder.png"), completed: {
            [weak self] (image, error, cacheType, imageURL)
            in
        })
        imageView.contentMode = .scaleAspectFill
        var shoptitle: String? = nil
        if let object = (dataSource[row] as? [AnyHashable : Any])?["shop_name"] {
            shoptitle = "\(object)"
        }
        cell?.txtDescription.text = shoptitle
        cell?.shareIcon.tag = indexPath.item
        cell?.cellImageView.tag = indexPath.item
        cell?.cellImageView.isUserInteractionEnabled = true
        cell?.shareIcon.addTarget(self, action: #selector(click(_:)), for: .touchUpInside)
        cell?.layer.shadowOpacity = 0.5
        cell?.layer.shadowOffset = CGSize(width: 1.0, height: 1.0)
        cell?.layer.shadowRadius = 10.0
        cell?.layer.shadowColor = UIColor.gray.cgColor
        return cell!
    }

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

        print(String(format: "Data Count :%lu", UInt(dataSource.count)))
        return dataSource.count
    } 

Answer 1

不要将cell存储为实例变量。

替换

cell = collectionView.dequeueReusableCell(withReuseIdentifier: CELL_IDENTIFIER, for: indexPath) as? CollectionViewCell

与

let cell = collectionView.dequeueReusableCell(withReuseIdentifier: CELL_IDENTIFIER, for: indexPath) as? CollectionViewCell

编辑:

使用collectionView.cellForItem(at: indexPath)在didSelectItemAt方法中获取单元格。