获取不到GridView中label控件的值

Question

环境：VS2005 C#                <asp:TemplateField HeaderText="index" Visible="False">
                    <HeaderStyle Font-Size="Small" />
                    <ItemTemplate>
                    <%# Eval("aindexa") %>
                    <asp:Label ID="Label_6" runat="server" Font-Size="Small" Text=""></asp:Label>
                    </ItemTemplate>
                </asp:TemplateField>注：数据库对应字段是数字类型
通过测试，绑定成功，数据库中数据都显示到了GridView对应列下单元格内获取：              
                for (int i = 0; i < GridView1.Rows.Count;++i )
                {
                    CheckBox cb = (CheckBox)GridView1.Rows[i].FindControl("checkbox1");
                    Label lb = (Label)GridView1.Rows[i].FindControl("Label_6");
                    string index = lb.Text;
                    //通过Cell属性获得到的文本也是空
                    if (cb != null && cb.Checked == true && index.Length > 0)
                    {
                        //经测试,同行的cb.Checked 成立时,index.Length却为0                    }
                }怎么获取不到label文字内容？有何解决办法？

Answer 1

checkbox1放在哪里
还有，这段for循环写在哪里，什么时候调用的

Answer 2

        <asp:GridView ID="GridView1" runat="server" AllowPaging="True" AutoGenerateColumns="False"
            Height="330px" Width="695px" DataSourceID="AccessDataSource2" BorderColor="Silver" BorderWidth="1px" OnRowDataBound="GridView1_RowDataBound" OnSelectedIndexChanged="GridView1_SelectedIndexChanged" OnDataBound="GridView1_DataBound">
            <Columns>
                <asp:TemplateField HeaderText="index" Visible="False">
                    <HeaderStyle Font-Size="Small" />
                    <ItemTemplate>
                    <%# Eval("aindexa") %>
                    <asp:Label ID="Label_6" runat="server" Font-Size="Small" Text=""></asp:Label>
                    </ItemTemplate>
                </asp:TemplateField>
                <asp:TemplateField HeaderText="选择">   
                <ItemTemplate>
                <asp:CheckBox ID="checkbox1" runat="server" />  
                </ItemTemplate>   
                    <ControlStyle Width="32px" />
                    <ItemStyle Width="28px" />
                    <HeaderStyle Font-Size="Small" />
                </asp:TemplateField>
点了某个checkbox后，再点击"删除所选行"按钮，在其回调函数中执行for(..,

Answer 3

<ItemTemplate><asp:Label ID="Label_6" runat="server" Font-Size="Small" Text=‘<%# Eval("aindexa") %>’></asp:Label>
</ItemTemplate>