登录网站是否成功获得响应？

Question

我正在尝试使用C＃登录Netflix。我有一些代码，但是我对HttpWebRequest的了解不那么多，因此任何帮助将不胜感激。谢谢！

private void Login()
    {
        HttpWebRequest request = (HttpWebRequest)WebRequest.Create("https://www.netflix.com/login");
        request.Method = "POST";
        request.UserAgent = "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:57.0) Gecko/20100101 Firefox/57.0";
        request.ContentType = "application/x-www-form-urlencoded";
        request.Accept = "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8";
        string postData = string.Format($"email={textEdit1.Text}&password={textEdit2.Text}&rememberMe=true&flow=websiteSignUp&mode=login&action=loginAction&withFields=email%2Cpassword%2CrememberMe%2CnextPage%2CshowPassword&authURL=+authUrl|1+&nextPage=https%3A%2F%2Fwww.netflix.com%2Fyouraccount&showPassword=");

        WebResponse response = request.GetResponse();
        MessageBox.Show(response.ToString());
        response.Close();
    }

我想知道如何检测登录是否成功（可能显示在MessageBox中）？