row header text problem not able to solve

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C#

C#4.0

Hi friends

i have develop two windows form .
in first form

the code for add row and column and set the rowheader text. the code is below

DataTable dt = new DataTable();

           for (int i = 0; i < columncount; i++)
           {
               dt.Columns.Add();
           }
           for (int j = 0; j < rowcount; j++)
           {
               dt.Rows.Add();

           }


           dataGridView1.DataSource = dt;
           for( int i=0;i<rowcount;i++)
           {
               dataGridView1.Rows[i].HeaderCell.Value = (i + 1).ToString();
           }

This code works for setting headercell of rows in gridview. and in the another form gridview design for time table it does not show the row headercell.value. the code is

   DataTable result= userdao.getdateanddayfortimetable1(comp);
            DataTable  period = userdao.getperiodfortimetable();
            int periodcount = period.Rows.Count;
            int daycount = result.Rows.Count;
            DataTable dt = new DataTable();
            for (int i = 0; i < periodcount; i++)
            {
                dt.Columns.Add();
            }
            for (int j = 0; j < daycount; j++)
            {
                dt.Rows.Add();
            }


            for (int k = 0; k < periodcount; k++)
            {

                dt.Columns[k].ColumnName = period.Rows[k]["PeriodNo"].ToString() + "(" + period.Rows[k]["StartTime"].ToString() + "-" + period.Rows[k]["EndTime"].ToString() + ")";
            }
            PLayer.TimeTable timetable = new PLayer.TimeTable();
            
timetable.timetablegrid.DataSource = dt;
            for (int i = 0; i < daycount; i++)
            {
                timetable.timetablegrid.Rows[i].HeaderCell.Value = result.Rows[i]["Working_day"].ToString();
                //timetable.timetablegrid.RowTemplate.Height = 25;
                //timetable.timetablegrid.RowHeadersDefaultCellStyle.Alignment = System.Windows.Forms.DataGridViewContentAlignment.MiddleCenter;
            }
            
            timetable.Show();

from yesterday i stuck with this problem. i dont know how to solve this problem. help me to solve this problem.
Thank you