Swift 设备上ScrollView为什么会将内容高度更改为随机值，而在预览上不会 优化后的标题：设备上ScrollView内容高度随机变化问题解决

我目前使用的是**Xcode 14.3.1版**(14E300c).

代码中的滚动视图有一个我用来迭代的对象数组ForEach().当用户滚动时，假设对象为30(出于演示目的，每个对象都有编号)，锚值为0.00135(您可以将其视为相对于所述对象的偏移值)，我希望用户能够在取消初始化视图之前返回到准确的位置；几乎与每个社交媒体应用程序完全一样.

我曾try 使用ScrollViewReader.scllTo(&lt；id:，锚:)来完成此操作，但无济于事.它与预览完美配合，但我一使用模拟器或设备(IPhone14)，它就开始随机调整我的ScrollView内容高度.

有没有人能解释一下，为什么这在预览版中可以完美地工作，但在设备上却不能；我如何才能在没有这个奇怪的错误的情况下在设备上工作？

因此，只有当您到达可滚动内容的末尾(底部)附近时，问题才会发生；奇怪的是，如果您滚动到可滚动内容的开头(顶部)附近，它会自动修复.

**// VIEW THAT IS PROBABLY CAUSING THE ISSUE**
struct ScrollViewWithSavedPosition: View {
    @ObservedObject var scrollViewSavedValue: ScrollViewSavedValue
    @State private var isViewLoaded: Bool = false
    let geoProxy: GeometryProxy
    let maxScrollableHeight: CGFloat = 4809
    
    var body: some View {
        ScrollViewReader { scrollProxy in
            ScrollView(showsIndicators: false) {
                LazyVStack {
                    ForEach(0..<34) { poster in
                        ZStack {
                            Rectangle()
                                .fill(.black)
                                .frame(width: geoProxy.size.width * 0.4,
                                       height: geoProxy.size.height * 0.2)
                            
                            Text("\(poster)")
                                .foregroundColor(.orange)
                        }
                    }
                }
                .id("scrollPosition")
                .background(
                    GeometryReader {
                        Color.orange
                            .preference(key: CGPointPK2.self,
                                        value: $0.frame(in: .global).origin)
                    }
                )
                .onPreferenceChange(CGPointPK2.self) { scrollPosition in
                    DispatchQueue.main.async {
                        isViewLoaded = true
                    }
                    
                    if isViewLoaded {
                        let offsetValue = (-1 * (scrollPosition.y - geoProxy.safeAreaInsets.top)) / maxScrollableHeight
                        scrollViewSavedValue.scrollOffsetValue = offsetValue
                    }
                    
                    print(scrollViewSavedValue.scrollOffsetValue)
                }
            }
            .onAppear {
                scrollProxy.scrollTo("scrollPosition", anchor: UnitPoint(x: 0, y: scrollViewSavedValue.scrollOffsetValue))
            }
        }
        .preferredColorScheme(.light)
    }
}

struct CGPointPK2: PreferenceKey {
    static var defaultValue: CGPoint = .zero
    static func reduce(value: inout CGPoint, nextValue: () -> CGPoint) { }
}

class ScrollViewSavedValue: ObservableObject {
    @Published var scrollOffsetValue: CGFloat = 0
    @Published var selectedTab: Int = 1
}

struct TabBarView: View {
    @ObservedObject var scrollViewSavedValue: ScrollViewSavedValue
    let geoProxy: GeometryProxy
    
    var body: some View {
        VStack {
            Spacer()
            
            ZStack {
                Rectangle()
                    .fill(.blue)
                    .frame(width: geoProxy.size.width, height: 80)
                
                HStack(spacing: 100) {
                    Button {
                        DispatchQueue.main.async {
                            scrollViewSavedValue.selectedTab = 1
                        }
                    } label: {
                        ZStack {
                            Circle()
                                .fill(.black)
                                .frame(width: 60, height: 60)
                            
                            Text("View 1")
                                .foregroundColor(.white)
                                .font(.system(size: 12))
                                .fontWeight(.bold)
                        }
                    }
                    
                    Button {
                        DispatchQueue.main.async {
                            scrollViewSavedValue.selectedTab = 2
                        }
                    } label: {
                        ZStack {
                            Circle()
                                .fill(.black)
                                .frame(width: 60, height: 60)
                            
                            Text("View 2")
                                .foregroundColor(.white)
                                .font(.system(size: 12))
                                .fontWeight(.bold)
                        }
                    }
                }
            }
        }
        .ignoresSafeArea()
    }
}

struct PresentationView: View {
    @StateObject private var scrollViewSavedValue = ScrollViewSavedValue()
    
    var body: some View {
        GeometryReader { geoProxy in
            switch scrollViewSavedValue.selectedTab {
            case 1:
                ScrollViewWithSavedPosition(scrollViewSavedValue: scrollViewSavedValue, geoProxy: geoProxy)
            default:
                Text("View 2")
                    .foregroundColor(.black)
            }
            
            TabBarView(scrollViewSavedValue: scrollViewSavedValue, geoProxy: geoProxy)
        }
    }
}