swift uicollectionviewcell

func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
    let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "CellIdentifier", for: indexPath) as! CustomCollectionViewCell
    
    // 设置单元格的数据
    cell.configure(with: dataSource[indexPath.item])
    
    return cell
}

override func viewDidLoad() {
    super.viewDidLoad()
    
    collectionView.register(CustomCollectionViewCell.self, forCellWithReuseIdentifier: "CellIdentifier")
}

class CustomCollectionViewCell: UICollectionViewCell {
    let label = UILabel()
    
    override init(frame: CGRect) {
        super.init(frame: frame)
        setupViews()
    }
    
    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    
    private func setupViews() {
        contentView.addSubview(label)
        label.translatesAutoresizingMaskIntoConstraints = false
        NSLayoutConstraint.activate([
            label.centerXAnchor.constraint(equalTo: contentView.centerXAnchor),
            label.centerYAnchor.constraint(equalTo: contentView.centerYAnchor)
        ])
    }
}

func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
    let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "CellIdentifier", for: indexPath) as! CustomCollectionViewCell
    
    // 异步加载图片
    DispatchQueue.global().async {
        if let image = self.loadImage(for: indexPath) {
            DispatchQueue.main.async {
                cell.imageView.image = image
            }
        }
    }
    
    return cell
}

private func loadImage(for indexPath: IndexPath) -> UIImage? {
    // 实现图片加载逻辑
    return UIImage(named: "exampleImage")
}