ios - UITabbarController 替换最后一个 View Controller

Question

我需要根据情况更换最后一个 View Controller 。进入 TabBarController 我有 4 个 View Controller ，最后一个 View Controller 是 LoginVC。如果我已经登录，我需要将 LoginVC 替换为 ProfileVC。

我尝试:

 func tabBarController(_ tabBarController: UITabBarController, shouldSelect viewController: UIViewController) -> Bool {
    if tabBarController.selectedIndex == 3 && !DefaultsManager.instance.getUserToken().isEmpty {
        showProfile()
        return false
    }
    return true
}

func tabBarController(_ tabBarController: UITabBarController, didSelect viewController: UIViewController) {
    if tabBarController.selectedIndex == 3 && !DefaultsManager.instance.getUserToken().isEmpty {
        showProfile()
    }
}

 func showProfile() {
    let profile = ProfileVC.instantiateNCFromStoryboard()
    self.viewControllers?[3] = profile
}

但这对我不起作用。

带有登录屏幕的屏幕

屏幕个人资料屏幕与我的条件

Answer 1

在 AppDelegate 中检查用户登录状态并更改最后一个 View Controller 及其 tabBarItem

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
    if let rootVC = self.window?.rootViewController as? UITabBarController, var viewControllers = rootVC.viewControllers {
        viewControllers.removeLast()
        if userLoggedIn {
            let profileVC = ProfileVC()
            //profileVC.tabBarItem = UITabBarItem(title: nil, image: UIImage(named: "imgName"), selectedImage: UIImage(named: "imgName"))
            profileVC.tabBarItem = UITabBarItem(title: "Profile", image: nil, selectedImage: nil)
            viewControllers.append(profileVC)
        } else {
            let loginVC = LoginVC()
            //loginVC.tabBarItem = UITabBarItem(title: nil, image: UIImage(named: "imgName"), selectedImage: UIImage(named: "imgName"))
            loginVC.tabBarItem = UITabBarItem(title: "Login", image: nil, selectedImage: nil)
            viewControllers.append(loginVC)
        }
        rootVC.viewControllers = viewControllers
    }
    return true
}

在 LoginVC 成功登录后，从 tabBarController 中删除 LoginVC 并添加 ProfileVC

@objc func loginBtnAction(_ sender: UIButton) {
    if var viewControllers = self.tabBarController?.viewControllers {
        viewControllers.removeLast()
        let profileVC = ProfileVC()
        //profileVC.tabBarItem = UITabBarItem(title: nil, image: UIImage(named: "imgName"), selectedImage: UIImage(named: "imgName"))
        profileVC.tabBarItem = UITabBarItem(title: "Profile", image: nil, selectedImage: nil)
        viewControllers.append(profileVC)
        self.tabBarController?.viewControllers = viewControllers
    }
}

在 ProfileVC 的 Logout 按钮操作中，从 tabBarController 中删除 ProfileVC 并添加 LoginVC

@objc func logoutBtnAction(_ sender: UIButton) {
    if var viewControllers = self.tabBarController?.viewControllers {
        viewControllers.removeLast()
        let loginVC = LoginVC()
        //loginVC.tabBarItem = UITabBarItem(title: nil, image: UIImage(named: "imgName"), selectedImage: UIImage(named: "imgName"))
        loginVC.tabBarItem = UITabBarItem(title: "Login", image: nil, selectedImage: nil)
        viewControllers.append(loginVC)
        self.tabBarController?.viewControllers = viewControllers
    }
}