如何在DataGrid中使用更新面板

Question

下面是我已经应用的代码，它给了我一个错误。

 <asp:TemplateColumn>
           <HeaderTemplate >
           <label>Article</label>
               </HeaderTemplate>       
              <ItemTemplate>      
           <asp:DropDownList ID="DrpArticle" runat="server" TabIndex="4" CssClass="form-control" AutoPostBack="true"
            OnSelectedIndexChanged = "DrpArticle_SelectedIndexChanged" AppendDataBoundItems = "true">      
                        </asp:DropDownList>                                  
                        <asp:UpdatePanel runat="server" ID="UpdatePanel1" UpdateMode="Conditional">
        <Triggers><asp:AsyncPostBackTrigger ControlID="DrpArticle" EventName="OnSelectedIndexChanged" /></Triggers>
        <ContentTemplate>
        <asp:Label ID="LblStock" runat="server" Text="..." ForeColor="#000066"></asp:Label>
        </ContentTemplate>
        </asp:UpdatePanel>
              </ItemTemplate>
               </asp:TemplateColumn>