呈现视图控制器太慢

Question

我已经在我的 Swift 应用程序中实现了 Firebase Google 登录。如果它已经是登录用户，我想先检查一下。我是这样做的：

override func viewDidLoad() {
        super.viewDidLoad()
        GIDSignIn.sharedInstance()?.presentingViewController = self
        GIDSignIn.sharedInstance().delegate = self

    }

    override func viewDidAppear(_ animated: Bool) {
        super.viewDidAppear(false)

        if Auth.auth().currentUser != nil {

          let storyboard = UIStoryboard(name: "Main", bundle: nil)
          let vc = storyboard.instantiateViewController(withIdentifier: "feedVC")
          vc.modalPresentationStyle = .fullScreen
          self.present(vc, animated: false)

        }
    }

现在我的问题是：它按我想要的方式工作，但速度很慢。在我的主页显示之前，我仍然可以快速查看登录屏幕。

现在如果我想将 currentUser 检查添加到 viewDidLoad，应用程序不会检查用户之前是否已经登录。

有什么建议吗？

Answer 1

在主线程上执行

 override func viewDidAppear(_ animated: Bool) {
        super.viewDidAppear(false)

        if Auth.auth().currentUser != nil {
    DispatchQueue.main.async {
     let storyboard = UIStoryboard(name: "Main", bundle: nil)
              let vc = storyboard.instantiateViewController(withIdentifier: "feedVC")
              vc.modalPresentationStyle = .fullScreen
              self.present(vc, animated: false)
    }
}

呈现视图控制器太慢

Presenting View Controller is too slow

viewdidload

viewdidappear

firebase

presentviewcontroller

swift