ios - 每次导航 Controller 弹出堆栈时都执行segue

Question

我有这个类，代码如下。基本上每次显示此页面时，都应在检查用户是否登录后立即执行 segue。

   class UserExistsOrNotViewController: UIViewController, UITabBarControllerDelegate {

    override func viewDidLoad() {
        super.viewDidLoad()
        tabBarController?.delegate = self
        // Do any additional setup after loading the view.
    }
    func tabBarController(tabBarController: UITabBarController, didSelectViewController viewController: UIViewController) {
        viewController.viewDidAppear(true)
        print("test")
    }

    override func viewDidAppear(animated: Bool) {
        super.viewDidAppear(animated)
        let realm = try! Realm()
        let openSearchItem = realm.objects(User).count
        if openSearchItem == 0 {
            performSegueWithIdentifier("notLoggedIn", sender: self)
        } else {
            performSegueWithIdentifier("loggedIn", sender: self)
        }

    }

我遇到的问题是，一旦我将上一页从堆栈中弹出，并且它返回到此代码，则不会执行转场。如果我将其放在 viewWillAppear 下，我的导航就会损坏。

Finishing up a navigation transition in an unexpected state. Navigation Bar subview tree might get corrupted)

我不知道现在该怎么办。我正在寻找什么:当我从导航 Controller 中弹出 View Controller 时，上面的类应该每次检查用户是否登录，并转到正确的页面。

Answer 1

如果您的 ViewWillAppear 被触发，但 ViewDidAppear 没有被触发。检查您是否缺少 super.viewDidAppear(animated)。请参阅讨论here