数组更改时SwiftUI列表不更新

import SwiftUI

struct ContentView: View {
    @State private var items = ["Item 1", "Item 2", "Item 3"]

    var body: some View {
        List(items, id: \.self) { item in
            Text(item)
        }
        .onAppear {
            DispatchQueue.main.asyncAfter(deadline: .now() + 2) {
                self.items.append("Item 4")
            }
        }
    }
}

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