C# 如何检查登录是否失败

以下代码由Fiddler生成，并在button_Click事件中调用

 //Create request to URL.
 HttpWebRequest request = (HttpWebRequest)WebRequest.Create("http://forums.codeguru.com/login.php?do=login");

 //Set request headers.
 request.UserAgent = "Mozilla/5.0 (Windows NT 5.1; rv:19.0) Gecko/20100101 Firefox/19.0";
 request.Accept = "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8";
 request.Headers.Set(HttpRequestHeader.AcceptLanguage, "en-US,en;q=0.5");
 request.Headers.Set(HttpRequestHeader.AcceptEncoding, "gzip, deflate");
 request.Referer = "http://forums.codeguru.com/";
 request.KeepAlive = false;
 request.ContentType = "application/x-www-form-urlencoded";

 //Set request method
 request.Method = "POST";

 // Disable 'Expect: 100-continue' behavior. More info: http://haacked.com/archive/2004/05/15/http-web-request-expect-100-continue.aspx
            request.ServicePoint.Expect100Continue = false;

 //Set request body.

 **// Fail**
  string body = @"vb_login_username=**userid**&vb_login_password=&vb_login_password_hint=Password&s=&securitytoken=guest&do=login&vb_login_md5password=a35cef11bdd55e36423f8d3b1ed69dea&vb_login_md5password_utf=a35cef11bdd55e36423f8d3b1ed69dea";

  byte[] postBytes = System.Text.Encoding.UTF8.GetBytes(body);
  request.ContentLength = postBytes.Length;
  Stream stream = request.GetRequestStream();
  stream.Write(postBytes, 0, postBytes.Length);
  stream.Close();

 //Get response to request.
 response = (HttpWebResponse)request.GetResponse();
 Stream responseStream = response.GetResponseStream();

 var reader = new System.IO.StreamReader(responseStream, Encoding.UTF8);
 string srcString = reader.ReadToEnd();

 }
 catch (WebException e)
 {
            //ProtocolError indicates a valid HTTP response, but with a non-200 status code (e.g. 304 Not Modified, 404 Not Found)
            if (e.Status == WebExceptionStatus.ProtocolError) response = (HttpWebResponse)e.Response;
            else return false;
 }
 catch (Exception)
 {
            if (response != null) response.Close();
            return false;
 }

return true;

}

单击按钮事件中的代码

       HttpWebResponse response;

        if (Request_forums_codeguru_com(out response))
        {
            //Success, possibly use response.

            HttpStatusCode status = response.StatusCode;

            // Status is alway OK

            response.Close();

            MessageBox.Show("Succesful login");

        }
        else
        {
            //Failure, cannot use response.

            MessageBox.Show("Unsuccesful login");
        }

但即使我输入了错误的密码，我也会得到HttpStatus作为OK。如何检查登录失败

在最后一个阶段，我将从Python服务器接收数据，因此上面只是一个测试

编辑：

当用户输入错误的用户id/密码组合时，他/她会看到以下内容：-

---

使用上述代码，您基本上是在模仿浏览器行为。网站必须返回一个错误的HTTPStatus，这仅仅是因为你的密码错了——看看目标网站是如何处理错误的密码的

如果您试图访问受保护的页面，此时可能会出现未经授权的访问错误并重定向到登录屏幕。取决于网站的设置方式

有两种可能性：

登录，然后尝试访问安全页面，检查 非授权访问错误或响应中返回的页面文本

检查响应的url-它是否已更改为您期望的url 为了成功登录

检查响应的文本并查找 例如“密码错误”、“密码无效”等

最终，除了选项2之外，没有可扩展或统一的方法来实现这一点。您将编写特定于站点的代码