另一个集合视图中集合视图单元格的约束

Question

我已经为 UICollectionView 创建了自定义类。我想将另一个 Collection 视图放入第一个类的单元格中。

import UIKit

class ModeCell: UICollectionViewCell {

    override init(frame: CGRect) {
        super.init(frame: frame)
        setupView()
    }


    let modeCollection : UICollectionView = {
        let layout = UICollectionViewFlowLayout()
        let collectionView = UICollectionView(frame: .zero, collectionViewLayout: layout)
        collectionView.backgroundColor = .cyan
        collectionView.translatesAutoresizingMaskIntoConstraints = false
        return collectionView
    }()

    func setupView(){
        backgroundColor = .red

        addSubview(modeCollection)
                addConstraints(NSLayoutConstraint.constraints(withVisualFormat: "H:[v0(180)]-20-|", options: NSLayoutFormatOptions(), metrics: nil, views: ["v0": modeCollection]))

                addConstraints(NSLayoutConstraint.constraints(withVisualFormat: "V:|-25-[v0(180)]", options: NSLayoutFormatOptions(), metrics: nil, views: ["v0": modeCollection]))

                addConstraints(NSLayoutConstraint.constraints(withVisualFormat: "H:|-30-[v0(160)]|", options: NSLayoutFormatOptions(), metrics: nil, views: ["v0": modeCollection]))

                addConstraints(NSLayoutConstraint.constraints(withVisualFormat: "V:|-95-[v0]", options: NSLayoutFormatOptions(), metrics: nil, views: ["v0": modeCollection]))

    }

    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
}

这段代码工作正常，但我想知道是否可以像我在其他项目中使用它们一样使用约束：

modeCollection.centerXAnchor.constraint(equalTo: .centerXAnchor).isActive = true modeCollection.bottomAnchor.constraint(equalTo: view.bottomAnchor).isActive = true modeCollection.widthAnchor.constraint(equalTo: view.widthAnchor).isActive = true modeCollection.heightAnchor.constraint(equalToConstant: 49).isActive = true

问题是我的新自定义类中没有“视图”，我也没有任何可参考的东西......

Answer 1

您不是为view 创建约束，而是为self 创建约束，这将引用UICollectionViewCell 本身（在您的情况下为ModeCell）。