create a column that will autogenerate the serial number of each row in GridView

I want to add auto generated Serial number as a column in grid view which is not from database.

So, I tried like this, and its working at all.

protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)

    {

        if (e.Row.RowType == DataControlRowType.DataRow)

        {

            Label lblSerial = (Label)e.Row.FindControl("lblSerial");

            lblSerial.Text = ((GridView1.PageIndex * GridView1.PageSize) + e.Row.RowIndex +                 1).ToString();

        }

    }

Or By Adding a Template column like the following we can do this,

<asp:TemplateField>

    <ItemTemplate>

        <%# Container.DataItemIndex + 1 %>

    </ItemTemplate>

</asp:TemplateField>