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

        public void postMultipartDataForm(string pUrl, Dictionary<string, string> pHeaders,
           Dictionary<string, string> pPostParams, HttpFormFile pFormFile,
            ProgressHandler pProgressHandler, CompletionHandler pCompletionHandler)
        {
            if (pFormFile == null)
            {
                if (pCompletionHandler != null)
                {
                    pCompletionHandler(ResponseInfo.fileError(new Exception("no file specified")), "");
                }
                return;
            }

            HttpWebRequest vWebReq = null;
            HttpWebResponse vWebResp = null;
            try
            {
                vWebReq = (HttpWebRequest)WebRequest.Create(pUrl);
                vWebReq.ServicePoint.Expect100Continue = false;
            }
            catch (Exception ex)
            {
                if (pCompletionHandler != null)
                {
                    pCompletionHandler(ResponseInfo.invalidRequest(ex.Message), "");
                }
                return;
            }

            try
            {
                vWebReq.UserAgent = this.getUserAgent();
                vWebReq.AllowAutoRedirect = false;
                vWebReq.Method = "POST";

                //create boundary
                string formBoundaryStr = this.createFormDataBoundary();
                string contentType = string.Format("multipart/form-data; boundary={0}", formBoundaryStr);
                vWebReq.ContentType = contentType;
                if (pHeaders != null)
                {
                    foreach (KeyValuePair<string, string> kvp in pHeaders)
                    {
                        if (!kvp.Key.Equals("Content-Type"))
                        {
                            vWebReq.Headers.Add(kvp.Key, kvp.Value);
                        }
                    }
                }

                //write post body
                vWebReq.AllowWriteStreamBuffering = true;

                byte[] formBoundaryBytes = Encoding.UTF8.GetBytes(string.Format("{0}{1}\r\n",
                    FORM_BOUNDARY_TAG, formBoundaryStr));
                byte[] formBoundaryEndBytes = Encoding.UTF8.GetBytes(string.Format("\r\n{0}{1}{2}\r\n",
                    FORM_BOUNDARY_TAG, formBoundaryStr, FORM_BOUNDARY_TAG));

                using (Stream vWebReqStream = vWebReq.GetRequestStream())
                {
                    //write params
                    if (pPostParams != null)
                    {
                        foreach (KeyValuePair<string, string> kvp in pPostParams)
                        {
                            vWebReqStream.Write(formBoundaryBytes, 0, formBoundaryBytes.Length);

                            byte[] formPartTitleData = Encoding.UTF8.GetBytes(
                                string.Format("Content-Disposition: form-data; name=\"{0}\"\r\n", kvp.Key));
                            vWebReqStream.Write(formPartTitleData, 0, formPartTitleData.Length);

                            byte[] formPartBodyData = Encoding.UTF8.GetBytes(string.Format("\r\n{0}\r\n", kvp.Value));
                            vWebReqStream.Write(formPartBodyData, 0, formPartBodyData.Length);
                        }
                    }

                    vWebReqStream.Write(formBoundaryBytes, 0, formBoundaryBytes.Length);

                    //write file name
                    string filename = pFormFile.Filename;
                    if (string.IsNullOrEmpty(filename))
                    {
                        filename = this.createRandomFilename();
                    }
                    byte[] filePartTitleData = Encoding.UTF8.GetBytes(
                                string.Format("Content-Disposition: form-data; name=\"file\"; filename=\"{0}\"\r\n", filename));
                    vWebReqStream.Write(filePartTitleData, 0, filePartTitleData.Length);
                    //write content type
                    string mimeType = FORM_MIME_OCTECT;  //!!!注意这里 @fengyh 2016-08-17 15:00
                    if (!string.IsNullOrEmpty(pFormFile.ContentType))
                    {
                        mimeType = pFormFile.ContentType;
                    }
                    byte[] filePartMimeData = Encoding.UTF8.GetBytes(string.Format("Content-Type: {0}\r\n\r\n", mimeType));
                    vWebReqStream.Write(filePartMimeData, 0, filePartMimeData.Length);

                    //write file data
                    switch (pFormFile.BodyType)
                    {
                        case HttpFileType.FILE_PATH:
                            try
                            {
                                FileStream fs = File.Open(pFormFile.BodyFile, FileMode.Open, FileAccess.Read);
                                this.writeHttpRequestBody(fs, vWebReqStream);
                            }
                            catch (Exception fex)
                            {
                                if (pCompletionHandler != null)
                                {
                                    pCompletionHandler(ResponseInfo.fileError(fex), "");
                                }
                            }
                            break;
                        case HttpFileType.FILE_STREAM:
                            this.writeHttpRequestBody(pFormFile.BodyStream, vWebReqStream);
                            break;
                        case HttpFileType.DATA_BYTES:
                            vWebReqStream.Write(pFormFile.BodyBytes, 0, pFormFile.BodyBytes.Length);
                            break;
                        case HttpFileType.DATA_SLICE:
                            vWebReqStream.Write(pFormFile.BodyBytes, pFormFile.Offset, pFormFile.Count);
                            break;
                    }

                    vWebReqStream.Write(formBoundaryEndBytes, 0, formBoundaryEndBytes.Length);
                    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;
                }
            }
        }