.net gridview 显示序号

<asp:TemplateField HeaderText="序号">
                                    <HeaderStyle BackColor="#6694B8" Font-Size="8pt" />
                                    <ItemTemplate>
                                        <%# Container.DataItemIndex+1 %>
                                    </ItemTemplate>
                                    <ItemStyle Width="6%" />
</asp:TemplateField>