SwiftUI - Split View on iPad problem

Is there an simple way to use the UISplitViewController with SwiftUI?

Currently I use a NavigationView. The problem is, that the ListView on the left only shows in landscape mode and not in portrait mode.

This is the example of my code:

Code Block SwiftUI
import SwiftUI
struct ContentView: View {
		var body: some View {
				NavigationView {
						ListView()
						DetailView()
			}.navigationViewStyle(DoubleColumnNavigationViewStyle())
		}
}
struct ContentView_Previews: PreviewProvider {
		static var previews: some View {
				ContentView()
		}
}
struct ListView: View {
		var body: some View {
				List(0 ..< 5) { item in
						NavigationLink(destination: DetailView()) {
								Text("List Item")
						}
				}
				.navigationTitle("My List")
		}
}
struct DetailView: View {
		var body: some View {
				Text("Hallo")
		}
}

I tested it with a padding after navigationViewStyle but the List View only displays in landscape mode.