post请求json内容丢失问题

今天在项目组用json传输数据 post方法提交 发现传输过去的数据json内的+ 号被直接干掉了.

后来传输之前直接先编码.

接收端:

  public void ProcessRequest(HttpContext context)
        {
            ReturnResult result = new ReturnResult();
            var method = context.Request.QueryString["method"].ToString();

            byte[] byts = new byte[HttpContext.Current.Request.InputStream.Length];
            HttpContext.Current.Request.InputStream.Read(byts, 0, byts.Length);
            string req = System.Text.Encoding.Default.GetString(byts);
            req = HttpContext.Current.Server.UrlDecode(req);


            //string p = @"d{4}-d{2}-d{2}sd{2}:d{2}:d{2}";
            //MatchEvaluator matchEvaluator = new MatchEvaluator(ConvertDateStringToJsonDate);
            //Regex reg = new Regex(p);
            //req = reg.Replace(req, matchEvaluator);


            try
            {
                if (context.Request.Params.Count > 0)
                {

                    if (!string.IsNullOrEmpty(method))
                    {
                        switch (method)
                        {

                            case DTKeys.URL_PARM_METHOD_SENDMESSAGEREMIND://来自用户信息认证的 附件上传
                                ContactMsg m = JsonHelper.FromJson<ContactMsg>(req);
                                SendMessageRemind(m);
                                break;

                            default:
                                break;
                        }
                    }
                }
                else
                {
                    result.Status = false;
                    result.Msg = "未检测的有效文件信息,或者您未登录";
                }
            }
            catch (Exception ex)
            {
                result.Status = false;
                result.Msg = ex.Message;
                Log4netHelper.WriteExceptionLog("Beta.ProductMarket.Web.Product.SendMsgToWX.ashx", ex);
            }
            context.Response.Clear();
            context.Response.ContentType = "text/html; charset=utf-8";
            context.Response.Write(JsonConvert.SerializeObject(result));
        }