使SwiftUI导航栏透明

import SwiftUI

struct ContentView: View {
    var body: some View {
        NavigationView {
            VStack {
                Text("Hello, World!")
            }
            .navigationBarHidden(true)
            .navigationBarTitle("")
            .background(Color.clear)
        }
    }
}

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