public class HttpHelper
    {
        public static CookieContainer Cookies = new CookieContainer();
        public static string GetHttpResponse(string url, string postdata)
        {
            try
            {
                HttpWebRequest MyRequest = (HttpWebRequest)WebRequest.Create(url);
                MyRequest.Method = "POST";
                MyRequest.ContentLength = postdata.Length;
                MyRequest.CookieContainer = Cookies;
                MyRequest.KeepAlive = true;
                MyRequest.AllowAutoRedirect = true;
                MyRequest.ContentType = "application/x-www-form-urlencoded";
                MyRequest.UserAgent = "    Mozilla/5.0 (Windows NT 5.1; rv:14.0) Gecko/20100101 Firefox/14.0.1";
                MyRequest.Accept = "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8";

                if (postdata != null)
                {
                    ASCIIEncoding MyEncoding = new ASCIIEncoding();
                    byte[] MyByte = MyEncoding.GetBytes(postdata);
                    Stream MyStream = MyRequest.GetRequestStream();
                    MyStream.Write(MyByte, 0, postdata.Length);
                    MyStream.Close();
                }

                string getContent = null;
                Encoding myEncoding = Encoding.GetEncoding("UTF-8");
                HttpWebResponse MyResponse = (HttpWebResponse)MyRequest.GetResponse();
                if (MyResponse.StatusCode == HttpStatusCode.OK)
                {

                    /*获取响应页面cookie*/
                   // MyResponse.Cookies = MyRequest.CookieContainer.GetCookies(MyRequest.RequestUri);


                    MessageBox.Show("adfdfasdf");
                    Stream MyNewStream = MyResponse.GetResponseStream();
                    StreamReader MyStreamReader = new StreamReader(MyNewStream, myEncoding);
                    getContent = MyStreamReader.ReadToEnd();
                    MyStreamReader.Close();
                }
                MyResponse.Close();
                return getContent;
            }
            catch (Exception)
            {
                return string.Empty;
            }
        }

    }