Swift NavigationStack 和 TabView 工具栏和标题不显示

TabView应该是你的顶层视图.

然后，每个选项卡都应该包含自己的NavigationStack个.例如:

enum Router {
    case screenA, screenB
}

struct ContentView: View {
    
    var body: some View {
        TabView() {
            FirstScreen()
            
            NavigationStack {
                Text("second")
                    .navigationTitle("second")
            }
            .tabItem {
                Label("second", systemImage: "2.circle")
            }
            NavigationStack {
                Text("third")
                    .navigationTitle("third")
            }
            .tabItem {
                Label("third", systemImage: "3.circle")
            }
            NavigationStack {
                Text("fourth")
                    .navigationTitle("fourth")
            }
            .tabItem {
                Label("fourth", systemImage: "4.circle")
            }

            NavigationStack {
                Text("fifth")
                    .navigationTitle("fifth")
            }
            .tabItem {
                Label("fifth", systemImage: "5.circle")
            }
        }
    }
}

struct FirstScreen: View {
    
    @State private var path: [Router] = []
    
    var body: some View {
        NavigationStack(path: $path) {
            VStack {
                Text("first")
                NavigationLink("Screen A", value: Router.screenA)
            }
            .navigationDestination(for: Router.self) { router in
                switch router {
                case .screenA:
                    VStack {
                        NavigationLink("Screen B", value: Router.screenB)
                    }
                    .navigationTitle("Screen A")
                    
                case .screenB:
                    VStack {
                        Button("Pop to root") {
                            path = []
                        }
                    }
                    .navigationTitle("Screen B")
                }
            }
            .navigationTitle("first")
        }
        .tabItem {
            Label("first", systemImage: "1.circle")
        }
        .task {
            print("First screen task")
        }
        .onAppear {
            print("First screen appears")
        }
    }
}