/// <summary>

         /// 对对象进行深度拷贝

         /// </summary>

         /// <param name="obj"></param>

         /// <returns></returns>

         private object Clone(object obj)

         {

             MemoryStream memory_stream = new MemoryStream();

             BinaryFormatter formatter = new BinaryFormatter();

             formatter.Serialize(memory_stream,obj);

             memory_stream.Position = ;

             return formatter.Deserialize(memory_stream);

         }