HttpWebRequest上傳文件(Excel等)

   
//上傳代碼
/// <summary>
        /// 文件上傳
        /// </summary>
        /// <param name="strAddress">路徑地址，不包括服務地址</param>
        /// <param name="postedFile"></param>
        /// <returns></returns>
        public static IResponseResult HttpPostFile(string strAddress, HttpPostedFile postedFile,string reFileName)
        {
            string url = ConfigHelper.GetConfigString("PAOfferSystemAddress") + strAddress;
            //1>建立請求
            HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
            //2>Cookie容器(保存cookie,只是上傳文件，則能夠註釋掉)
            //request.CookieContainer = cookieContainer;
            request.Method = "POST";
            request.Timeout = 120000;
            request.Credentials = System.Net.CredentialCache.DefaultCredentials;
            request.KeepAlive = true;

            string boundary = "----------------------------" + DateTime.Now.Ticks.ToString("x");//分界線
            byte[] boundaryBytes = System.Text.Encoding.UTF8.GetBytes("\r\n--" + boundary + "\r\n");

            request.ContentType = "multipart/form-data; boundary=" + boundary;//內容類型

            //3>表單數據模板
            //string formdataTemplate = "\r\n--" + boundary + "\r\nContent-Disposition: form-data; name=\"{0}\";\r\n\r\n{1}";
            //4>讀取流
            byte[] buffer = new byte[postedFile.ContentLength];
            postedFile.InputStream.Read(buffer, 0, buffer.Length);

            //5>寫入請求流數據
            string strHeader = "Content-Disposition:application/x-www-form-urlencoded; name=\"{0}\";filename=\"{1}\"\r\nContent-Type:{2}\r\n\r\n";
            strHeader = string.Format(strHeader,
                                     "filedata",
                //postedFile.FileName,
                                     reFileName + postedFile.FileName,
                                     postedFile.ContentType);
            //6>HTTP請求頭
            byte[] byteHeader = System.Text.ASCIIEncoding.UTF8.GetBytes(strHeader);
            StringBuilder sbBody=new StringBuilder ();
            sbBody.Append(System.Text.Encoding.UTF8.GetString(boundaryBytes));
            sbBody.Append(System.Text.Encoding.UTF8.GetString(byteHeader));
            sbBody.Append(System.Text.Encoding.UTF8.GetString(buffer));
            sbBody.Append(System.Text.Encoding.UTF8.GetString(System.Text.Encoding.UTF8.GetBytes("\r\n--" + boundary + "--\r\n")));
            string headValue = Encrpt(sbBody.ToString());//加密
            request.Headers.Add("OfferServiceAuthorization", headValue);
            request.Headers.Add("CustomID", ConfigurationManager.AppSettings["CustomID"]);

            try
            {
                using (Stream stream = request.GetRequestStream())
                {
                    #region 寫入請求流(表單數據)
                    //寫入請求流(表單數據)
                    //if (null != parameters)
                    //{
                    //    foreach (KeyValuePair<string, object> item in parameters)
                    //    {
                    //        stream.Write(boundaryBytes, 0, boundaryBytes.Length);//寫入分界線
                    //        byte[] formBytes = System.Text.Encoding.UTF8.GetBytes(string.Format(formdataTemplate, item.Key, item.Value));
                    //        stream.Write(formBytes, 0, formBytes.Length);
                    //    }
                    //}
                    #endregion
                    //6.0>分界線============================================注意：缺乏次步驟，可能致使遠程服務器沒法獲取Request.Files集合
                    stream.Write(boundaryBytes, 0, boundaryBytes.Length);
                    //6.1>請求頭
                    stream.Write(byteHeader, 0, byteHeader.Length);
                    //6.2>把文件流寫入請求流
                    stream.Write(buffer, 0, buffer.Length);
                    //6.3>寫入分隔流
                    byte[] trailer = System.Text.Encoding.UTF8.GetBytes("\r\n--" + boundary + "--\r\n");
                    stream.Write(trailer, 0, trailer.Length);
                    //6.4>關閉流
                    stream.Close();
                }
                string responseContent = "";
                HttpWebResponse response = (HttpWebResponse)request.GetResponse();
                using (StreamReader streamReader = new StreamReader(response.GetResponseStream()))
                {
                    responseContent = streamReader.ReadToEnd();
                    response.Close();
                    request.Abort();
                }

                return JsonConvertHelper.DataContractToModel<IResponseResult>(responseContent);
            }
            catch (Exception ex)
            {
                throw new Exception(ex.Message);
            }
        }

//服務器代碼

   HttpPostedFile file = Context.Request.Files["filedata"];//獲取上傳文件
            if (null == file || file.ContentLength == 0)
            {
                IResponseResult responseResult = new IResponseResult();
                responseResult.Status = ResponseStatus.Fail;
                responseResult.Message = "Upload file is invalid";
                //to json返回結果
                string toJson = JsonConvertHelper.ToJson(responseResult);
                Response.Write(toJson);
            }
            else
            {
                string filePath = Server.MapPath("~/File/Excel");
                if (!Directory.Exists(filePath))//判斷文件夾是否存在 
                {
                    Directory.CreateDirectory(filePath);//不存在則建立文件夾 
                }
                file.SaveAs(string.Format("{0}/{1}", filePath, file.FileName));
                IResponseResult responseResult = new IResponseResult();
                responseResult.Status = ResponseStatus.Success;
                string toJson = JsonConvertHelper.ToJson(responseResult);
                Response.Write(toJson);
            }