如何在隐藏选项卡视图控制器中单击“后退”按钮时显示选项卡

// 在AppDelegate中设置选项卡视图控制器作为根视图控制器
func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
    let tabBarController = UITabBarController()
    // 添加其他子视图控制器到选项卡视图控制器中
    // ...
    
    let navigationController = UINavigationController(rootViewController: tabBarController)
    window?.rootViewController = navigationController
    window?.makeKeyAndVisible()
    
    return true
}

// 在需要显示选项卡的视图控制器中添加后退按钮
class HiddenTabViewController: UIViewController {
    override func viewDidLoad() {
        super.viewDidLoad()
        
        // 创建后退按钮
        let backButton = UIBarButtonItem(title: "后退", style: .plain, target: self, action: #selector(backButtonTapped))
        navigationItem.leftBarButtonItem = backButton
    }
    
    @objc func backButtonTapped() {
        // 返回上一个视图控制器
        navigationController?.popViewController(animated: true)
    }
}