/// <summary>

         /// 把对象序列化 JSON 字符串

         /// </summary>

         /// <typeparam name="T">对象类型</typeparam>

         /// <param name="obj">对象实体</param>

         /// <returns>JSON字符串</returns>

         public static string GetJson<T>(T obj)

         {

             //记住 添加引用 System.ServiceModel.Web

             /**

              * 如果不添加上面的引用,System.Runtime.Serialization.Json; Json是出不来的哦

              * */

             DataContractJsonSerializer json = new DataContractJsonSerializer(typeof(T));

             using (MemoryStream ms = new MemoryStream())

             {

                 json.WriteObject(ms, obj);

                 string szJson = Encoding.UTF8.GetString(ms.ToArray());

                 return szJson;

             }

         }