望高手解答,合并DataTable相同行数据 显示总价格？

void Main()

{

 

   DataTable dt=new DataTable();

   dt.Columns.Add("UsedDay",typeof(int));

   dt.Columns.Add("MTID",typeof(int));

   dt.Columns.Add("maxDate");

   dt.Columns.Add("TMoney",typeof(int));

   dt.Rows.Add(1,1,"2011-07-04 10:35:29.330",12);

   dt.Rows.Add(3,1,"2011-07-05 09:46:38.277",108);

   dt.Rows.Add(5,1,"2011-07-05 09:46:04.793",60);

   dt.Rows.Add(30,1,"2011-07-05 09:46:04.793",204);

   dt.Rows.Add(90,1,"2011-07-05 09:46:13.590",612);

   dt.Rows.Add(365,1,"2011-07-04 18:53:16.650",568);

   dt.Rows.Add(730,1,"2011-07-04 18:52:57.903",1136);

   dt.Rows.Add(1095,1,"2011-07-04 18:52:05.623",1704);

   dt.Rows.Add(1460,1,"2011-06-30 09:28:16.220",0);

   dt.Rows.Add(3,2,"2011-07-05 09:47:57.123",36);

   dt.Rows.Add(5,2,"22011-07-05 09:48:07.470",60);

   dt.Rows.Add(30,2,"2011-07-05 09:47:50.850",68);

   dt.Rows.Add(1095,2,"2011-07-01 17:05:25.810",1704);

   var query=from r in dt.AsEnumerable()

             let temp=r.Field<int>("UsedDay")<30?1:r.Field<int>("UsedDay")%30==0?30:r.Field<int>("UsedDay")%365==0?365:1

			 group r by new {UsedDay=temp,MTID=r.Field<int>("MTID")} into g

			 select new

			 {

			    UsedDay=g.Key.UsedDay,

				MTID=g.Key.MTID,

				maxDate=g.FirstOrDefault().Field<string>("maxDate"),

				TMoney=g.Sum(t=>t.Field<int>("TMoney")),

				Count=g.Count()

			 };

    Console.WriteLine("UsedDay\tMTID\t\tmaxDate\t\tTMoney\tCount");

	query.ToList().ForEach(q=>Console.WriteLine("{0}\t{1}\t{2}\t{3}\t{4}",q.UsedDay,q.MTID,q.maxDate,q.TMoney,q.Count));

	

	/*

	UsedDay	MTID		maxDate		TMoney	Count

	1	1	2011-07-04 10:35:29.330	180	3

	30	1	2011-07-05 09:46:04.793	816	2

	365	1	2011-07-04 18:53:16.650	3408	4

	1	2	2011-07-05 09:47:57.123	96	2

	30	2	2011-07-05 09:47:50.850	68	1

	365	2	2011-07-01 17:05:25.810	1704	1

	*/

}