DataTable dt = new DataTable();
            dt.Columns.Add("Name", typeof(string));
            dt.Columns.Add("Age", typeof(int));

            List<TestObj> tList = new List<TestObj>();
            for (int i = 0; i < tList.Count; i++)
            {
                DataRow dr = dt.NewRow();
                dr[0] = tList[i].Name;
                dr[1] = tList[i].Age;
                dt.Rows.Add(dr);
            }
            DataSet ds = new DataSet();
            ds.Tables.Add(dt);