SwiftUI:如何在父视图的中心叠加图像？

import SwiftUI

struct ContentView: View {
    var body: some View {
        VStack {
            Text("父视图")
                .font(.largeTitle)
                .padding()
                .background(Color.blue)
                .foregroundColor(.white)
            
            Image("overlay_image")
                .resizable()
                .frame(width: 100, height: 100)
                .overlay(
                    Text("叠加的图像")
                        .font(.headline)
                        .foregroundColor(.white)
                        .padding()
                        .background(Color.black.opacity(0.7))
                        .cornerRadius(10)
                )
        }
    }
}

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