UIViewRepresentable内容未更新

Question

我已经为滚动视图实现了UIViewRepresentable，因为我需要滚动内容的索引。除滚动内容未更新的问题外，其他所有功能均正常运行。

struct SwiftyUIScrollView<Content>: UIViewRepresentable where Content: View {
typealias UIViewType = Scroll

var content: () -> Content
var pagingEnabled: Bool = false
var hideScrollIndicators: Bool = false
@Binding var shouldUpdate: Bool
@Binding var currentIndex: Int

var onScrollIndexChanged: ((_ index: Int) -> Void)

public init(pagingEnabled: Bool,
            hideScrollIndicators: Bool,
            currentIndex: Binding<Int>,
            shouldUpdate: Binding<Bool>,
            @ViewBuilder content: @escaping () -> Content, onScrollIndexChanged: @escaping ((_ index: Int) -> Void)) {
    self.content = content
    self.pagingEnabled = pagingEnabled
    self._currentIndex = currentIndex
    self._shouldUpdate = shouldUpdate
    self.hideScrollIndicators = hideScrollIndicators
    self.onScrollIndexChanged = onScrollIndexChanged
}

func makeUIView(context: UIViewRepresentableContext<SwiftyUIScrollView>) -> UIViewType {
    let hosting = UIHostingController(rootView: content())
    let view = Scroll(hideScrollIndicators: hideScrollIndicators, isPagingEnabled: pagingEnabled)
    view.scrollDelegate = context.coordinator
    view.alwaysBounceHorizontal = true
    view.addSubview(hosting.view)
    makefullScreen(of: hosting.view, to: view)
    return view
}

class Coordinator: NSObject, ScrollViewDelegate {
    func didScrollToIndex(_ index: Int) {
        self.parent.onScrollIndexChanged(index)
    }

    var parent: SwiftyUIScrollView

    init(_ parent: SwiftyUIScrollView) {
        self.parent = parent
    }
}

func makeCoordinator() -> SwiftyUIScrollView<Content>.Coordinator {
    Coordinator(self)
}

func updateUIView(_ uiView: Scroll, context: UIViewRepresentableContext<SwiftyUIScrollView<Content>>) {
    if shouldUpdate {
        uiView.scrollToIndex(index: currentIndex)
    }
}

func makefullScreen(of childView: UIView, to parentView: UIView) {
    childView.translatesAutoresizingMaskIntoConstraints = false
    childView.leftAnchor.constraint(equalTo: parentView.leftAnchor).isActive = true
    childView.rightAnchor.constraint(equalTo: parentView.rightAnchor).isActive = true
    childView.topAnchor.constraint(equalTo: parentView.topAnchor).isActive = true
    childView.bottomAnchor.constraint(equalTo: parentView.bottomAnchor).isActive = true
}
}

然后创建一个新类来处理滚动视图的委托。

class Scroll: UIScrollView, UIScrollViewDelegate {

var hideScrollIndicators: Bool = false
var scrollDelegate: ScrollViewDelegate?
var tileWidth = 270
var tileMargin = 20

init(hideScrollIndicators: Bool, isPagingEnabled: Bool) {
    super.init(frame: CGRect.zero)
    showsVerticalScrollIndicator = !hideScrollIndicators
    showsHorizontalScrollIndicator = !hideScrollIndicators
    delegate = self
    self.isPagingEnabled = isPagingEnabled
}

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

func scrollViewDidEndDecelerating(_ scrollView: UIScrollView) {
    let currentIndex = scrollView.contentOffset.x / CGFloat(tileWidth+tileMargin)
    scrollDelegate?.didScrollToIndex(Int(currentIndex))
}

func scrollViewDidScroll(_ scrollView: UIScrollView) {
    let currentIndex = scrollView.contentOffset.x / CGFloat(tileWidth+tileMargin)
    scrollDelegate?.didScrollToIndex(Int(currentIndex))
}

func scrollToIndex(index: Int) {
    let newOffSet = CGFloat(tileWidth+tileMargin) * CGFloat(index)
    contentOffset = CGPoint(x: newOffSet, y: contentOffset.y)
}
}

现在要实现scrollView，我使用了以下代码。

@State private var activePageIndex: Int = 0
@State private var shouldUpdateScroll: Bool = false
@State private var tables: [Table] = []

SwiftyUIScrollView(pagingEnabled: false, hideScrollIndicators: true, currentIndex: $activePageIndex, shouldUpdate: $shouldUpdateScroll, content: {
            HStack(spacing: 20) {
                ForEach(self.tables, id: \.id) { data in
                        self.cardView(data: data)
                }
            }
            .padding(.horizontal, 30.0)
        }, onScrollIndexChanged: { (newIndex) in
           shouldUpdateScroll = false
           activePageIndex = index
            // Your own required handling
        })


func getTheNextView(data: Any) -> AnyView {
    // Return the required destination View
}

如果最初 tables 数组具有4个对象，则将该数组更新为5个对象时，还应在滚动视图中包含新视图。但这永远不会更新。任何帮助将不胜感激。