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public static void PrintPersons()         {             //准备数据             DataTable dt = new DataTable();             dt.Columns.Add(new DataColumn("ID", typeof(int)));             dt.Columns.Add(new DataColumn("UserName", typeof(string)));             dt.Columns.Add(new DataColumn("DeptNo", typeof(string)));             dt.Columns.Add(new DataColumn("DeptName", typeof(string)));             DataRow drTemp = null;             for (int i = 10; i <= 18; i++)             {                 drTemp = dt.NewRow();                 drTemp["ID"] = i;                 drTemp["UserName"] = "姓名" + i.ToString();

                if (i < 15)                 {                     drTemp["DeptNo"] = "0001";                     drTemp["DeptName"] = "人事部";                 }                 else                 {                     drTemp["DeptNo"] = "0002";                     drTemp["DeptName"] = "生产部";                 }                 dt.Rows.Add(drTemp);             }

            Console.WriteLine("分组前：");             foreach (DataRow row in dt.Rows)             {                 Console.WriteLine(string.Format("{0} {1} {2} {3} ", row.ItemArray));             }             Console.WriteLine("");

            Console.WriteLine("分组后：");

            //Linq分组查询，并按分组显示人员明细             var query = from g in dt.AsEnumerable()                         group g by new { t1 = g.Field<string>("DeptNo"), t2 = g.Field<string>("DeptName") } into companys                         select new { DeptNo = companys.Key.t1, DeptName = companys.Key.t2, StallInfo = companys };

            foreach (var userInfo in query)             {                 System.Collections.Generic.List<DataRow> dataRows = userInfo.StallInfo.ToList();

                Console.WriteLine(string.Format("{0}({1})人员名单: ", userInfo.DeptName, userInfo.DeptNo));                 foreach (System.Data.DataRow dr in dataRows)                 {                     Console.WriteLine(string.Format("{0} {1} ", dr.ItemArray));                 }             }             Console.ReadLine();         }

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原文：https://www.cnblogs.com/qiu18359243869/p/10337388.html