swift 弹出提示框

    func showMsgbox(_message: String, _title: String = "提示"){

        let alert = UIAlertController(title: _title, message: _message, preferredStyle: UIAlertControllerStyle.alert)
        let btnOK = UIAlertAction(title: "好的", style: .default, handler: nil)
        alert.addAction(btnOK)
        self.present(alert, animated: true, completion: nil)

    }

    @IBAction func btnLoginClick(_ sender: Any) {

if tvName.text == ""{

showMsgbox(_message: "请输入帐号")

return

}

if tvPassword.text == ""{

showMsgbox(_message: "请输入密码")

return

}

    }