SwiftUI:如何知道视图何时在滚动视图中移动？

import SwiftUI

struct ContentView: View {
    var body: some View {
        ScrollView {
            VStack {
                ForEach(1...10, id: \.self) { index in
                    Text("Item \(index)")
                        .onAppear {
                            print("Item \(index) appeared")
                        }
                }
            }
        }
    }
}

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