ios - Swift 3 Firebase : current user login success, 事件已在 Firebase 控制台中删除此用户

Question

在登录表单中通过代码成功创建 Firebase 用户后。我在 Firebase 控制台中删除了这个新用户，退出了应用程序。再次打开应用程序时，它仍然提示登录成功，用户已被管理员删除。这是为什么，如何在登录表单中知道用户已删除？

引用我下面的登录表单代码:

override func viewDidLoad() {
    super.viewDidLoad()

    // get the current user is by setting a listener on the Auth object:
    FIRAuth.auth()!.addStateDidChangeListener() { auth, user in
        if user != nil {
            // User is signed in.
            print("start login success: " + (user?.email)! )
            //self.performSegue(withIdentifier: loginToList, sender: nil)
        } else {
            // No user is signed in.
            print("No user is signed in.")
        }

    }

    //get the currently signed-in user by using the currentUser property. If a user isn't signed in, currentUser is nil:
    if let curUser = FIRAuth.auth()?.currentUser {
        // User is signed in.
        print("start current user: " + curUser.email! )
    } else {
        // No current user is signed in.
        print("Currently, no user is signed in.")
    }
}
}

示例代码来自 https://firebase.google.com/docs/auth/ios/manage-users

Answer 1

因为用户仍然处于登录状态。第一步是注销，您可以在 applicationDidEnterBackground 函数内的 appDelegate 中进行。只需这样调用:
尝试! FIRAuth.auth()!.signOut()

 func applicationDidEnterBackground(_ application: UIApplication) {
    // Use this method to release shared resources, save user data, invalidate timers, and store enough application state information to restore your application to its current state in case it is terminated later.
    // If your application supports background execution, this method is called instead of applicationWillTerminate: when the user quits.

     try! FIRAuth.auth()!.signOut()
}

第二步是进行新登录(例如，如果用户允许将电子邮件和密码保存在...userDefault...中)并在 applicationDidBecomeActive 函数中获取有关用户登录的新信息。

func applicationDidBecomeActive(_ application: UIApplication) {
    // Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface.

  // Check if the User data exist

    let User = UserDefaults.standard

    guard let myEmail = User.object(forKey: "userName") as? String  else {

        print("No User")

        return
    }

    //Check if the user wants the automatic access

    guard User.object(forKey: "automaticLogIn") as! Bool else {

        print("Automatic LogIn disable")
        return
    }

    // Now you can to do the automatic login

    let password = User.object(forKey: "password") as! String

    FIRAuth.auth()?.signIn(withEmail: myEmail, password: password, completion: { (user, error) in

        if error == nil{

            print("logIn succesfull")

        }else{

            let typeError = FIRAuthErrorCode(rawValue: error!._code)!
            switch typeError {
            case .errorCodeUserNotFound:
                print("user not found")
            case .errorCodeWrongPassword:
                print("wrong password")
            default:
                break

            }
        }
    })


}

现在您可以在需要的地方调用 FIRAuth.auth()!.addStateDidChangeListener()，例如在 viewDidLoad 中

override func viewDidLoad() {
    super.viewDidLoad()

 //  Save the user data inside userDefault, you can do it where you want.... like a form inside an alertView

    let User = UserDefaults.standard
    User.set("userEmail...", forKey: "userName")
    User.set("UserPassword", forKey: "password")
    User.set(true, forKey: "automaticLogIn")

FIRAuth.auth()!.addStateDidChangeListener() { auth, user in
        if user != nil {
            // User is signed in.
            print("start login success: " + (user?.email)! )
            //self.performSegue(withIdentifier: loginToList, sender: nil)
        } else {
            // No user is signed in.
            print("No user is signed in.")
        }

    }

}