datatable运用groupby进行分组统计

如何在datatable中进行分组，并且计算分组后每组的数量，想了一下，可以使用LINQ来实现datatable分组。代码如下

?

效果

区域??? 库房????????? 数量
北京---北京仓库---1

北京---上海仓库---1

上海---上海仓库---2

?

DataTable dt = new DataTable("cart");
??????????? DataColumn dc1 = new DataColumn("areaid", Type.GetType("System.String"));
??????????? DataColumn dc2 = new DataColumn("house", Type.GetType("System.String"));
??????????? DataColumn dc3 = new DataColumn("seq", Type.GetType("System.String"));
??????????? DataColumn dc4 = new DataColumn("remark", Type.GetType("System.String"));

??????????? dt.Columns.Add(dc1);
??????????? dt.Columns.Add(dc2);
??????????? dt.Columns.Add(dc3);
??????????? dt.Columns.Add(dc4);

??????????? DataRow dr = dt.NewRow();
??????????? dr["areaid"] = "北京";
??????????? dr["house"] = "北京仓库";
??????????? dr["seq"] = "2";
??????????? dr["remark"] = "货到付款";
??????????? dt.Rows.Add(dr);

??????????? DataRow dr1 = dt.NewRow();
??????????? dr1["areaid"] = "北京";
??????????? dr1["house"] = "上海仓库";
??????????? dr1["seq"] = "1";
??????????? dr1["remark"] = "货到付款";
??????????? dt.Rows.Add(dr1);

??????????? DataRow dr2 = dt.NewRow();
??????????? dr2["areaid"] = "上海";
??????????? dr2["house"] = "上海仓库";
??????????? dr2["seq"] = "1";
??????????? dr2["remark"] = "货到付款";
??????????? dt.Rows.Add(dr2);

??????????? DataRow dr3 = dt.NewRow();
??????????? dr3["areaid"] = "上海";
??????????? dr3["house"] = "北京仓库";
??????????? dr3["seq"] = "1";
??????????? dr3["remark"] = "货到付款";
??????????? dt.Rows.Add(dr3);
??????????? var query = from t in dt.AsEnumerable()
??????????????????????? group t by new { t1 = t.Field<string>("areaid"), t2 = t.Field<string>("seq") } into m
??????????????????????? select new
??????????????????????? {
??????????????????????????? areaid = m.Key.t1,
??????????????????????????? seq = m.Key.t2,
??????????????????????????? house = m.First().Field<string>("house"),
??????????????????????????? rowcount = m.Count()
??????????????????????? };
??????????? Console.WriteLine("区域 " + "? 库房" + "?? 数量");
??????????? foreach (var item in query.ToList())
??????????? {
??????????????? if (item.rowcount > 1)
??????????????? {
??????????????????? Console.WriteLine(item.areaid + "---" + item.house);
??????????????? }
??????????????? Console.WriteLine(item.areaid + "---" + item.house + "---" + item.rowcount);
??????????????? Console.WriteLine("\r\n");
??????????? }
??????????? Console.ReadKey();