[HttpPost] 
　　　　 [Route("api/callback")]
        public async Task<dynamic> CallBackByJdy()
        {
            Dictionary<string, string> dic = new Dictionary<string, string>();
            try
            {
                var stream = new MemoryStream();
                await Request.Content.CopyToAsync(stream);
                stream.Seek(0, SeekOrigin.Begin);
                var body = await new StreamReader(stream).ReadToEndAsync();//获取回调的请求体 body;
　　　　　　　　　　
　　　　　　　　　　//可对body进行处理 业务逻辑code

                HttpResponseMessage response = Request.CreateResponse(HttpStatusCode.OK);
                foreach (var value in response.RequestMessage.Headers)
                {
                    dic.Add(value.Key, value.Value.First());
                    //获取请求头存入dic字典中
                }

                var uri = response.RequestMessage.RequestUri;//获取请求地址
                var nonce = HttpUtility.ParseQueryString(uri.Query).Get("nonce");//请求地址中包含的参数
                var timestamp = HttpUtility.ParseQueryString(uri.Query).Get("timestamp");
                var signature = dic.FirstOrDefault(t=>t.Key=="X-JDY-Signature").Value;//读取字典中的请求头数据
                return ResponseMessage(response);//返回响应
            }
            catch (Exception ex)
            {
                HttpResponseMessage message = Request.CreateErrorResponse(HttpStatusCode.InternalServerError, "fail", ex);
                return ResponseMessage(message);
                //throw;
            }
        }