HttpWebRequest

Question

我有个问题我用HttpWebRequest来实现自动登陆网站问题，总是登陆不了代码如下： IHTMLDocument2 doc = (IHTMLDocument2)Parse(html);
            HTMLFormElement formEle = (HTMLFormElement)doc.forms.item(0, 0);
            StringBuilder sb = new StringBuilder("__EVENTTARGET=&__EVENTARGUMENT=&__LASTFOCUS=&");
            foreach (IHTMLElement ele in formEle)
            {
                if (ele.tagName.ToLower() == "input")
                {
                    IHTMLInputElement iEle = (IHTMLInputElement)ele;
                    if (iEle.name.IndexOf("UserName") != -1)
                    {
                        sb.Append(HttpUtility.UrlEncode(iEle.name) + "=" + HttpUtility.UrlEncode("sq324044") + "&");
                    }
                    else if (iEle.name.IndexOf("Password") != -1)
                    {
                        sb.Append(HttpUtility.UrlEncode(iEle.name) + "=" + HttpUtility.UrlEncode("sakura88") + "&");
                    }
                    else
                    {
                        sb.Append(HttpUtility.UrlEncode(iEle.name) + "=" + HttpUtility.UrlEncode(iEle.value) + "&");
                    }
                }
                if (ele.tagName.ToLower() == "select")
                {
                    IHTMLSelectElement sEle = (IHTMLSelectElement)ele;
                    sb.Append(HttpUtility.UrlEncode(sEle.name) + "=" + HttpUtility.UrlEncode(sEle.value) + "&");
                }
            }            sb.Remove(sb.Length - 1, 1);            ServicePointManager.ServerCertificateValidationCallback =
                new RemoteCertificateValidationCallback(ValidateServerCertificate);   ASCIIEncoding encoding = new ASCIIEncoding();
            byte[] data = encoding.GetBytes(sb.ToString());   
            HttpWebRequest myRequest = (HttpWebRequest)WebRequest.Create("https://216.152.164.80/Members/LoggedInPage.aspx");            myRequest.Method = "POST";
            myRequest.ContentType = "application/x-www-form-urlencoded";
            myRequest.ContentLength = data.Length;
            Stream newStream = myRequest.GetRequestStream();            // Send the data.  
            newStream.Write(data, 0, data.Length);
            newStream.Close();            // Get response  
            HttpWebResponse myResponse = (HttpWebResponse)myRequest.GetResponse();
            StreamReader reader = new StreamReader(myResponse.GetResponseStream(), Encoding.Default);
            string content = reader.ReadToEnd();
            Console.WriteLine(content);
            return content;