Swift - Firebase 函数signInWithEmail 在第一次调用时不执行

@IBAction func loginEmailButton(sender: AnyObject) {
        FIRAuth.auth()?.signInWithEmail(email.text!, password: password.text!, completion: { (user, error) in
            if error != nil {
                if let errCode = FIRAuthErrorCode(rawValue: error!.code) {
                    switch errCode {
                    case .ErrorCodeInvalidEmail:
                        self.emailLoginStatus = "invalid email"
                    case .ErrorCodeUserDisabled:
                        self.emailLoginStatus = "User account disabled"
                    case .ErrorCodeWrongPassword:
                        self.emailLoginStatus = "Wrong Password"
                    case .ErrorCodeUserNotFound:
                        self.emailLoginStatus = "User not found"
                    case .ErrorCodeNetworkError:
                        self.emailLoginStatus = "Could not connect"
                    default:
                        self.emailLoginStatus = "Login Error"
                    }
                }
            }else{
                self.emailLoginStatus = "Logged"
            }
        })

        if self.emailLoginStatus == "Logged"{
            self.performSegueWithIdentifier("emailLoginToSearchSegue", sender: self)
        }else{
            showAlert(emailLoginStatus)
        }

}

我确实一步步调试了代​​码，情况是这样的：当我点击loginEmailButton第一次，邮箱和密码参数设置为signInWithEmail函数，但该函数不执行（调试的下一步直接退出函数而不运行完成块）。

然后模拟器会显示没有文本的警报消息，但如果我关闭警报并点击loginEmailButton再次，signInWithEmail正确执行并显示带有正确消息的警报。我什至尝试更新 Firebase pod，但问题仍然存在。

有什么建议吗？谢谢！

它的异步问题。signInWithEmail对服务器进行异步调用，这意味着此调用将加载到不同的网络线程中，这需要一些时间才能完成，但由于您的performSegueWithIdentifier被放在completionBlock之外，所以它甚至在登录完成之前就被执行，但是当您下次按下按钮时，您的用户之前已经从您的第一次调用中登录了，所以它会继续...

只需将

self.performSegueWithIdentifier("emailLoginToSearchSegue", sender: self)

在 - 的里面signInWithEmail完成块（）。

@IBAction func loginEmailButton(sender: AnyObject) {
    FIRAuth.auth()?.signInWithEmail(email.text!, password: password.text!, completion: { (user, error) in
        if error != nil {
            if let errCode = FIRAuthErrorCode(rawValue: error!.code) {
                switch errCode {
                case .ErrorCodeInvalidEmail:
                    self.emailLoginStatus = "invalid email"
                case .ErrorCodeUserDisabled:
                    self.emailLoginStatus = "User account disabled"
                case .ErrorCodeWrongPassword:
                    self.emailLoginStatus = "Wrong Password"
                case .ErrorCodeUserNotFound:
                    self.emailLoginStatus = "User not found"
                case .ErrorCodeNetworkError:
                    self.emailLoginStatus = "Could not connect"
                default:
                    self.emailLoginStatus = "Login Error"
                }
            }
        }else{
            self.performSegueWithIdentifier("emailLoginToSearchSegue", sender: self)
        }
    })
}