快速POST代码，异常截获机制

 System.Net.HttpWebRequest request = System.Net.HttpWebRequest.Create("httpxxxxxxxxxxxxxxxxxxxx") as System.Net.HttpWebRequest;

                request.Method = "POST";
                request.ContentType = "application/x-www-form-urlencoded";
               
                request.Timeout = 3000;

            
                string datastr = "xxxxxxxxxxxxxxxxxxxxxxxxxx";

                ASCIIEncoding encoding = new ASCIIEncoding();
                byte[] data = encoding.GetBytes(datastr);

                request.ContentLength = data.Length;
                Stream newStream = request.GetRequestStream();
                // Send the data.
                newStream.Write(data, 0, data.Length);
                newStream.Close();
                System.Net.HttpWebResponse response = null;
                try
                {
                response = (System.Net.HttpWebResponse)request.GetResponse();
                }
                catch (System.Net.WebException ex)
                {

                    response = ex.Response as System.Net.HttpWebResponse;
                }
                System.IO.StreamReader reader = new System.IO.StreamReader(response.GetResponseStream(), Encoding.UTF8);
                string resultstr = reader.ReadToEnd();
                response.Close();