使用者驗證：
之前有實作過使用者驗證信的部分：
送驗證信：

firebaseUser?.sendEmailVerification { _ in
}

是否成功驗證

func emailVerified(){
    Auth.auth().currentUser?.reload(completion: { (error) in
        if let error = error {
            print(error)
        } else {
            if Auth.auth().currentUser != nil && Auth.auth().currentUser!.isEmailVerified {
                self.userIsEmailVerified = true
            } else {
                self.userIsEmailVerified = false
            }
        }
    })
}

code:

if (Auth.auth().currentUser?.email == GlobalAppSetting.shared.username && GlobalAppSetting.shared.username == emailTextField.text!) {
    emailVerified()
    Auth.auth().signIn(withEmail: self.emailTextField.text!, password: self.passwordTextField.text!, completion: { (user, error) in
        self.emailVerified()
        guard self.userIsEmailVerified else {
            TAlertView.showAlertWith(title: "", message: "Not Verified！", delegate: self, confirm: nil)
            return
        }
        if user != nil {
            // 登入成功了
            TAlertView.showAlertWith(title: "", message: "Successfull！", delegate: self, confirm: nil)
        }else{
            // 登入失敗了
                TAlertView.showAlertWith(title: "", message: "Failed to Login！", delegate: self, confirm: nil)
        }
                })