如何更改标签栏项目

Question

我有4个标签栏项，并将登录页面放在tab4上。登录后如何更改tab4配置文件视图。当我没有登录时，tab4是登录视图。

我已经创建了UItabbarcontroller。我可以在加载应用程序时更改tab4。但是，当我登录或注销运行时间时，无法重新加载tab4。

let logined = UserDefaults.standard.bool(forKey: "logined")
        let profileVC:ProfileViewController = storyboard?.instantiateViewController(withIdentifier: "ProfilePage") as! ProfileViewController
        let loginVC:LoginViewController = storyboard?.instantiateViewController(withIdentifier: "LoginPage") as! LoginViewController
if logined{
        var viewControllers = self.viewControllers
        viewControllers?.remove(at: 3)
        viewControllers?.append(profileVC)
        self.viewControllers = viewControllers
}else{
        var viewControllers = self.viewControllers
        viewControllers?.remove(at: 3)
        viewControllers?.append(loginVC)
        self.viewControllers = viewControllers
}