สอบถามเรื่องการใช้ Dropdown list ไปใส่ใน GridView ครับ

private DataTable DT1()
    {

        DropDownList dropDownRepeat = new DropDownList();
       
        DataTable dt = new DataTable();
        dropDownRepeat.ID = "dlRepeat";
        dropDownRepeat.AutoPostBack = true;

        //ListItem listItem = new ListItem();
        //listItem.Text = "D";
        //listItem.Value = "day";
        //dropDownRepeat.Items.Insert(0, listItem);
        //listItem.Text = "M";
        //listItem.Value = "month";
        //dropDownRepeat.Items.Insert(1, listItem);
        //listItem.Text = "Y";
        //listItem.Value = "year";
        //dropDownRepeat.Items.Insert(2, listItem);

        dropDownRepeat.Items.Clear();
        dropDownRepeat.DataTextField = "D";
        dropDownRepeat.DataValueField = "dayly";
        dropDownRepeat.DataTextField = "M";
        dropDownRepeat.DataValueField = "month";
        dropDownRepeat.DataTextField = "Y";
        dropDownRepeat.DataValueField = "dayly";
       
 
        if (!IsPostBack)

        {
            dropDownRepeat.SelectedIndex = 0;
        }

        dropDownRepeat.DataSource = dt;
        dropDownRepeat.DataBind();  
        dt.Columns.Add("Name");
        dt.Columns.Add("Time");
        dt.Columns.Add("Repeat");

        DataRow dr = dt.NewRow();
        dr["Name"] = "test1";
        dr["Time"] = "test2"; 
        dr["repeat"] = dropDownRepeat;      
        dt.Rows.Add(dr);

        dr = dt.NewRow();
        dr["Name"] = "test3";
        dr["Time"] = "test4";
        dr["Repeat"] = dropDownRepeat;
        dt.Rows.Add(dr);

        dtg.DataSource = dt;
        dtg.DataBind();
        //GridView.DataSource = dt;
        //GridView.DataBind();

        return dt;


    }