如何获得datagrid里面的dropdownlist的ID
<asp:TemplateColumn HeaderText="选择">
<ItemTemplate>
<asp:Label id=Label3 runat="server" Text='<%# DataBinder.Eval(Container, "DataItem.RQ") %>'>
</asp:Label>
</ItemTemplate>
<EditItemTemplate>
<asp:DropdownList id="DropdownList1" runat="server"></asp:DropdownList>
</EditItemTemplate>
</asp:TemplateColumn>
VB.net中,在编辑状态下,怎样得到DropdownList的id