其实很简单，只要将这一类的东东都放到 <EditItemTemplate>里就行了
<EditItemTemplate>
<ASP:DropDownList ID="cmbCategories" Runat="server"></ASP:DropDownList>
</EditItemTemplate>
就可以在CS中操作它了，填充数据，等等等等
<ASP:datagrid id="dgProducts" runat="server" AutoGenerateColumns="False" DataKeyField="ProductID" CellPadding="4" BorderWidth="1px" BorderColor="#DEDFDE" BackColor="White" BorderStyle="None" GridLines="Vertical" ForeColor="Black">
<SelectedItemStyle Font-Bold="True" ForeColor="White" BackColor="#CE5D5A"></SelectedItemStyle>
<AlternatingItemStyle BorderStyle="Double" BorderColor="#0000C0" BackColor="White"></AlternatingItemStyle>
<ItemStyle CSSClass="header" BackColor="#F7F7DE"></ItemStyle>
<HeaderStyle Font-Bold="True" ForeColor="White" BackColor="#6B696B"></HeaderStyle>
<FooterStyle BackColor="#CCCC99"></FooterStyle>
<Columns>
<ASP:BoundColumn DataField="ProductName" HeaderText="Name"></ASP:BoundColumn>
<ASP:TemplateColumn HeaderText="Category">
<ItemTemplate>
<%# Container.DataItem("CategoryName")%>
</ItemTemplate>
<EditItemTemplate>
<ASP:DropDownList ID="cmbCategories" Runat="server"></ASP:DropDownList>
</EditItemTemplate>
</ASP:TemplateColumn>
<ASP:EditCommandColumn ButtonType="PushButton" UpdateText="Update" CancelText="Cancel" EditText="Edit"></ASP:EditCommandColumn>
</Columns>
</ASP:datagrid>
