深度复制

       public static  T Clone<T>(T RealObject)
       {
           using (Stream stream = new MemoryStream())
           {
               XmlSerializer serializer = new XmlSerializer(typeof(T));
               serializer.Serialize(stream, RealObject);
               stream.Seek(0, SeekOrigin.Begin);
               return (T)serializer.Deserialize(stream);
           }
       }