Qiniu.Http.HttpManager.postForm C# (CSharp) Method

        public void postForm(string pUrl, Dictionary<string, string> pHeaders,
            Dictionary<string, string[]> pPostParams, CompletionHandler pCompletionHandler)
        {
            HttpWebRequest vWebReq = null;
            HttpWebResponse vWebResp = null;
            try
            {
                vWebReq = (HttpWebRequest)WebRequest.Create(pUrl);
            }
            catch (Exception ex)
            {
                if (pCompletionHandler != null)
                {
                    pCompletionHandler(ResponseInfo.invalidRequest(ex.Message), "");
                }
                return;
            }

            try
            {
                vWebReq.UserAgent = this.getUserAgent();
                vWebReq.AllowAutoRedirect = false;
                vWebReq.Method = "POST";
                vWebReq.ContentType = FORM_MIME_URLENCODED;
                if (pHeaders != null)
                {
                    foreach (KeyValuePair<string, string> kvp in pHeaders)
                    {
                        if (!kvp.Key.Equals("Content-Type"))
                        {
                            vWebReq.Headers.Add(kvp.Key, kvp.Value);
                        }
                    }
                }

                // format the post body
                StringBuilder vPostBody = new StringBuilder();
                if (pPostParams != null)
                {
                    foreach (KeyValuePair<string, string[]> kvp in pPostParams)
                    {
                        foreach (string vVal in kvp.Value)
                        {
                            vPostBody.AppendFormat("{0}={1}&",
                                Uri.EscapeDataString(kvp.Key), Uri.EscapeDataString(vVal));
                        }
                    }
                    // write data
                    vWebReq.AllowWriteStreamBuffering = true;
                    using (Stream vWebReqStream = vWebReq.GetRequestStream())
                    {
                        vWebReqStream.Write(Encoding.UTF8.GetBytes(vPostBody.ToString()),
                            0, vPostBody.Length - 1);
                        vWebReqStream.Flush();
                    }
                }

                //fire request
                vWebResp = (HttpWebResponse)vWebReq.GetResponse();
                handleWebResponse(vWebResp, pCompletionHandler);
            }
            catch (WebException wexp)
            {
                // FIX-HTTP 4xx/5xx Error 2016-11-22, 17:00 @fengyh
                HttpWebResponse xWebResp = wexp.Response as HttpWebResponse;
                handleErrorWebResponse(xWebResp, pCompletionHandler, wexp);
            }
            catch (Exception exp)
            {
                handleErrorWebResponse(vWebResp, pCompletionHandler, exp);
            }
            finally
            {
                if (vWebResp != null)
                {
                    vWebResp.Close();
                    vWebResp = null;
                }

                if (vWebReq != null)
                {
                    vWebReq.Abort();
                    vWebReq = null;
                }
            }
        }

        public void reqPostTest()
        {
            HttpManager target = new HttpManager();
            string pUrl = "http://ip.taobao.com/service/getIpInfo.php";
            Dictionary<string, string> pHeaders = new Dictionary<string, string>();
            Dictionary<string, string[]> pPostParams = new Dictionary<string, string[]>();
            pPostParams.Add("ip", new string[] { "100.123.199.44", "100.123.199.45" });

            CompletionHandler pCompletionHandler = new CompletionHandler(delegate(ResponseInfo respInfo, string response)
            {
                Assert.AreEqual(respInfo.StatusCode, 200);
            });
            target.postForm(pUrl, pHeaders, pPostParams, pCompletionHandler);
        }