public string ReComposeJson_Identify(string json_in)
        {
            json_get_minutiae json_from_WebAPI;

            //de-serialize json string from web api.
            using (var ms = new MemoryStream(Encoding.Unicode.GetBytes(json_in)))
            {
                DataContractJsonSerializer deseralizer = new DataContractJsonSerializer(typeof(json_get_minutiae));
                json_from_WebAPI = (json_get_minutiae)deseralizer.ReadObject(ms);// //反序列化ReadObject
            }

            //put together as new serialize json string as server need
            json_srv_indetify json_to_srv = new json_srv_indetify();
            string            ret_str;

            using (var ms = new MemoryStream())
            {
                DataContractJsonSerializer seralizer = new DataContractJsonSerializer(typeof(json_srv_indetify));

                //assign one json to another json
                json_to_srv.encMinutiae = json_from_WebAPI.data.encMinutiae;
                json_to_srv.eSkey       = json_from_WebAPI.data.eSkey;
                json_to_srv.iv          = json_from_WebAPI.data.iv;

                //write to stream
                seralizer.WriteObject(ms, json_to_srv);
                ms.Position = 0;
                StreamReader sr = new StreamReader(ms, Encoding.UTF8);
                ret_str = sr.ReadToEnd();
                sr.Close();
            }
            return(ret_str);
        }
        public string BuildJson_Identify(string encMinutiae, string eSkey, string iv)
        {
            //put together as new serialize json string as server need
            json_srv_indetify json_to_srv = new json_srv_indetify();
            string            ret_str;

            using (var ms = new MemoryStream())
            {
                DataContractJsonSerializer seralizer = new DataContractJsonSerializer(typeof(json_srv_indetify));

                //assign one json to another json
                json_to_srv.encMinutiae = encMinutiae;
                json_to_srv.eSkey       = eSkey;
                json_to_srv.iv          = iv;

                //write to stream
                seralizer.WriteObject(ms, json_to_srv);
                ms.Position = 0;
                StreamReader sr = new StreamReader(ms, Encoding.UTF8);
                ret_str = sr.ReadToEnd();
                sr.Close();
            }
            return(ret_str);
        }