本示例使用Beta
5版本说明中记录的新环境var，该环境使用了value属性。在更高的Beta中对其进行了更改，以使用wrappedValue属性。该示例现在是GM版本的最新示例。此完全相同的概念可消除由.sheet修饰符呈现的模态视图。

import SwiftUI

struct DetailView: View {
    @Environment(\.presentationMode) var presentationMode: Binding<PresentationMode>
    var body: some View {
        Button(
            "Here is Detail View. Tap to go back.",
            action: { self.presentationMode.wrappedValue.dismiss() }
        )
    }
}

struct RootView: View {
    var body: some View {
        VStack {
            NavigationLink(destination: DetailView())
            { Text("I am Root. Tap for Detail View.") }
        }
    }
}

struct ContentView: View {
    var body: some View {
        NavigationView {
            RootView()
        }
    }
}