asp.net Gridview de Sıra Kolonu Eklemek

protectedvoid GridView1_RowDataBound1(object sender, GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.DataRow)
{
(e.Row.FindControl("lblSira") as Label).Text = (e.Row.RowIndex + 1 + (GridView1.PageIndex * 10)).ToString();
}
}