Swift UI scrollTo正确的锚点参数

import SwiftUI

struct ContentView: View {
    @State private var scrollToItem = 0
    
    var body: some View {
        ScrollView {
            VStack(spacing: 20) {
                ForEach(0..<100, id: \.self) { index in
                    Text("Item \(index)")
                        .frame(height: 50)
                        .background(Color.gray.opacity(0.2))
                        .onTapGesture {
                            scrollToItem = index
                        }
                }
            }
        }
        .frame(height: 300)
        .background(Color.white)
        .animation(.spring(), value: scrollToItem)
        .onPreferenceChange(ScrollToPreferenceKey.self) { value in
            if let index = value {
                withAnimation(.spring()) {
                    let offset = CGFloat(index * 50)
                    ScrollViewReader { proxy in
                        proxy.scrollTo(.offset(x: 0, y: offset), anchor: .top)
                    }
                }
            }
        }
    }
}

struct ScrollToPreferenceKey: PreferenceKey {
    static var defaultValue: Int? = nil
    
    static func reduce(value: inout Int?, nextValue: () -> Int?) {
        value = nextValue()
    }
}

struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        ContentView()
    }
}