public string WebClientPost(string PostData, string PostUrl, string Type)

  {

      string postString = PostData;

      byte[] postData = Encoding.UTF8.GetBytes(postString);//编码，尤其是汉字，事先要看下抓取网页的编码方式

      string url = PostUrl;//地址

      WebClient webClient = new WebClient();

      byte[] responseData = null;

      if (Type == "post")

      {

          webClient.Headers.Add("Content-Type", "application/x-www-form-urlencoded");//采取POST方式必须加的header，如果改为GET方式的话就去掉这句话即可

          responseData = webClient.UploadData(url, "POST", postData);//得到返回字符流

      }

      else

      {

          responseData = webClient.UploadData(url, "GET", postData);//得到返回字符流

      }

      string srcString = Encoding.UTF8.GetString(responseData);//解码

      return srcString;

  }

            string _Result = PostData(Appid, AppKey, imgSrc, "", "post");

            JObject jsonData = JObject.Parse(_Result);

            JArray jsonFace = jsonData.GetValue("face") as JArray;

            if (jsonFace == null)

            {

                msg = "err" + "," + "格式不对";

            }

            else

            {

                int height = ;

                int width = ;

                int center_x = ;

                int center_y = ;

                string sex = "";

                if (jsonFace != null && jsonFace.Count > )

                {

                    height = int.Parse(jsonFace[]["position"]["height"].ToString());

                    width = int.Parse(jsonFace[]["position"]["width"].ToString());

                    center_x = int.Parse(jsonFace[]["position"]["center"]["x"].ToString());

                    center_y = int.Parse(jsonFace[]["position"]["center"]["y"].ToString());

                    sex = jsonFace[]["attribute"]["gender"].ToString();

                }
             }

 Dictionary<string, object> objJson = JsonConvert.DeserializeObject<Dictionary<string, object>>(request);

            string state = objJson["state"].ToString();

string imgSrc = context.Request.Form["ImgUrl"].ToString();  //服务器连接 

string FileDir = "/PublicResource/";

           string AppName = System.Configuration.ConfigurationManager.AppSettings["AppName"];

           if (!string.IsNullOrEmpty(AppName))

           {

               FileDir = "/PublicResource/" + AppName + "/";

           }

           Guid NewId = Guid.NewGuid();

           WebClient wc = new WebClient();

           string WXPath = context.Server.MapPath(FileDir + NewId.ToString() + ".jpg");

           wc.DownloadFile(imgSrc, WXPath);