swift - 如何将 SwiftUI View 设置为 CollectionView 的单元格

Question

我找到了 SwiftUI Text View 非常容易使用自定义设计创建标签。所以我想将它用作常规 UIKit UICollectionViewCell 的 View 。

到目前为止，这是我的代码(您可以在 Xcode 11 中复制和粘贴)。

import SwiftUI
import UIKit

struct ContentView: View {
    var body: some View {
        CollectionComponent()
    }
}

#if DEBUG
struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        ContentView()
    }
}
#endif

struct CollectionComponent : UIViewRepresentable {
    func makeCoordinator() -> CollectionComponent.Coordinator {
        Coordinator(data: [])
    }

    class Coordinator: NSObject, UICollectionViewDataSource, UICollectionViewDelegate {
        var data: [String] = []

        init(data: [String]) {

            for index in (0...1000) {
                self.data.append("\(index)")
            }
        }

        func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
            data.count
        }

        func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
            let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "cell", for: indexPath) as! GenericCell
            cell.customView.rootView = AnyView(
                Text(data[indexPath.item]).font(Font.title).border(Color.red)
            )
            return cell
        }
    }


    func makeUIView(context: Context) -> UICollectionView {
        let layout = UICollectionViewFlowLayout()
        layout.estimatedItemSize = UICollectionViewFlowLayout.automaticSize
        layout.scrollDirection = .vertical
        let cv = UICollectionView(frame: .zero, collectionViewLayout: layout)
        cv.dataSource = context.coordinator
        cv.delegate = context.coordinator
        cv.register(GenericCell.self, forCellWithReuseIdentifier: "cell")

        cv.backgroundColor = .white
        layout.minimumInteritemSpacing = 0
        layout.minimumLineSpacing = 0
        return cv
    }
    func updateUIView(_ uiView: UICollectionView, context: Context) {

    }
}


open class GenericCell: UICollectionViewCell {
    public var customView = UIHostingController(rootView: AnyView(Text("")))
    public override init(frame: CGRect) {
        super.init(frame: frame)
        configure()
    }
    public required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        configure()
    }
    private func configure() {
        contentView.addSubview(customView.view)
        customView.view.preservesSuperviewLayoutMargins = false
        customView.view.translatesAutoresizingMaskIntoConstraints = false

        NSLayoutConstraint.activate([
            customView.view.leftAnchor.constraint(equalTo: contentView.layoutMarginsGuide.leftAnchor),
            customView.view.rightAnchor.constraint(equalTo: contentView.layoutMarginsGuide.rightAnchor),
            customView.view.topAnchor.constraint(equalTo: contentView.layoutMarginsGuide.topAnchor),
            customView.view.bottomAnchor.constraint(equalTo: contentView.layoutMarginsGuide.bottomAnchor),
        ])
    }
}

第一个画面不错。



但是当我滚动经过可见屏幕的末尾时，它看起来像



我在自动调整单元格大小时做错了什么吗？或者这只是更多的 SwiftUI 错误？

[编辑]
我已经接受了 SwiftUI 的答案，但是如果有人可以按照此问题的要求为我提供使用 UIKit 的修复程序，我会接受。

Answer 1

我做了一些修改并且它有效，但我认为这不是最佳实践。

import SwiftUI
import UIKit

struct ContentView: View {
    var body: some View {
        CollectionComponent()
    }
}

#if DEBUG
struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        ContentView()
    }
}
#endif

struct CollectionComponent : UIViewRepresentable {
    func makeCoordinator() -> CollectionComponent.Coordinator {
        Coordinator(data: [])
    }

    class Coordinator: NSObject, UICollectionViewDataSource, UICollectionViewDelegate {
        var data: [String] = []

        init(data: [String]) {

            for index in (0...1000) {
                self.data.append("\(index)")
            }
        }

        func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
            data.count
        }
        func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
            return CGSize(width: collectionView.frame.width/2.5, height: collectionView.frame.width/2)
        }

        func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
            let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "cell", for: indexPath) as! GenericCell

            cell.customView?.rootView = Text(data[indexPath.item])

            return cell
        }
    }


    func makeUIView(context: Context) -> UICollectionView {
        let layout = UICollectionViewFlowLayout()
        layout.scrollDirection = .vertical
        let cvs = UICollectionView(frame: .zero, collectionViewLayout: layout)
        cvs.dataSource = context.coordinator
        cvs.delegate = context.coordinator
        cvs.register(GenericCell.self, forCellWithReuseIdentifier: "cell")

        cvs.backgroundColor = .white
        return cvs
    }
    func updateUIView(_ uiView: UICollectionView, context: Context) {

    }
}


public class GenericCell: UICollectionViewCell {

    public var textView = Text("")
    public var customView: UIHostingController<Text>?
    public override init(frame: CGRect) {
        super.init(frame: .zero)


        customView = UIHostingController(rootView: textView)
        customView!.view.translatesAutoresizingMaskIntoConstraints = false
        contentView.addSubview(customView!.view)

        customView!.view.topAnchor.constraint(equalTo: contentView.topAnchor).isActive = true
        customView!.view.leftAnchor.constraint(equalTo: contentView.leftAnchor).isActive = true
        customView!.view.rightAnchor.constraint(equalTo: contentView.rightAnchor).isActive = true
        customView!.view.bottomAnchor.constraint(equalTo: contentView.bottomAnchor).isActive = true
    }
    public required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
}