SwiftUI: VStack/HStack/ZStack拖动手势不起作用

import SwiftUI

struct ContentView: View {
    @State private var offset = CGSize.zero
    
    var body: some View {
        VStack {
            Text("Hello, SwiftUI!")
                .font(.largeTitle)
                .padding()
            
            HStack {
                Text("VStack")
                    .font(.title)
                    .padding()
                
                Spacer()
                
                Text("HStack")
                    .font(.title)
                    .padding()
            }
            
            ZStack {
                Rectangle()
                    .fill(Color.blue)
                    .frame(width: 200, height: 200)
                    .offset(offset)
                    .gesture(
                        DragGesture()
                            .onChanged { value in
                                self.offset = value.translation
                            }
                            .onEnded { value in
                                self.offset = .zero
                            }
                    )
                
                Text("ZStack")
                    .font(.title)
                    .foregroundColor(.white)
            }
        }
    }
}

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