SwiftUI -按条件添加导航栏按钮

import SwiftUI

struct ContentView: View {
    @State private var isLoggedIn = false

    var body: some View {
        NavigationView {
            VStack {
                Toggle(isOn: $isLoggedIn) {
                    Text("Logged In")
                }
                .padding()

                if isLoggedIn {
                    NavigationLink(destination: ProfileView()) {
                        Text("Profile")
                            .foregroundColor(.blue)
                    }
                } else {
                    NavigationLink(destination: LoginView()) {
                        Text("Login")
                            .foregroundColor(.blue)
                    }
                }
            }
            .navigationTitle("Home")
            .navigationBarItems(trailing: Button(action: {
                // 处理按钮点击事件
            }) {
                Image(systemName: "plus")
            })
        }
    }
}

struct ProfileView: View {
    var body: some View {
        Text("Profile View")
            .navigationTitle("Profile")
    }
}

struct LoginView: View {
    var body: some View {
        Text("Login View")
            .navigationTitle("Login")
    }
}