第一種,使用Linq查詢表達式,code如下

DataTable testtable = new DataTable();      testtable.Columns.Add("ID");      testtable.Columns.Add("ProductName");      testtable.Rows.Add("1", "1");      testtable.Rows.Add("1", "1");      testtable.Rows.Add("1", "1");      testtable.Rows.Add("2", "2");      testtable.Rows.Add("3", "3");      DataTable finalltable = new DataTable();      finalltable = testtable.Clone();      finalltable.Clear();            var rows = from row in testtable.AsEnumerable() group row by row["ID"] into myrow select myrow.FirstOrDefault();      foreach (DataRow row in rows)      {        finalltable.ImportRow(row);      }

第二種方法

利用dataview來過濾datatable

testtable = testtable.DefaultView.ToTable(true, new string[] { "ID", "ProductName" });