请教各位朋友一个遍历CheckBox取其值的问题，先谢谢！

Question

以下是我的代码（这里用到了GridView嵌套GridView，即要取得GridView2中CheckBox的值。）：<asp:GridView ID="GridView1" runat="server" DataKeyNames="id" Width="100%" AutoGenerateColumns="False" BorderStyle="None" CellPadding="0" GridLines ="None" >
                            <Columns>
                <asp:TemplateField>
                <ItemTemplate>
                <TABLE id="Table2" cellSpacing="0" cellPadding="0" width="100%" align="center" border="0">
                <TR>
                <TD colSpan="2" width="100%">
                <asp:Label id="Label1" runat="server" Text='<%# Container.DataItemIndex+1 %>'></asp:Label>
                <asp:Label id="Label2" runat="server" Text='<%# Eval("topic","、{0}") %>'></asp:Label>
                 <asp:Label id="Label40" runat="server" Text='<%# Eval("id") %>' Visible="False"></asp:Label>                 
            </TD>
                </TR>
                <TR>
                <TD width="5%"></TD>
                <TD width="95%">
                <asp:GridView ID="GridView2" runat="server" Width="100%" DataKeyNames="a_id,id" DataSource='<%# GetTitleID(Eval("id").ToString()) %>' AutoGenerateColumns="False" BorderStyle="None" CellPadding="0" GridLines ="None">
                                                        <Columns>
                                            <asp:TemplateField>
                                            <ItemTemplate>
                                            <TABLE id="Table3" cellSpacing="0" cellPadding="0" width="100%" align="center" border="0">
                                            <TR>
                                            <TD colSpan="2">
                                            <asp:Label id="Label5" runat="server" Text='<%# Container.DataItemIndex+1 %>'></asp:Label>
                                            <asp:Label id="Label6" runat="server" Text='<%# Eval("tiweng","、{0}") %>'>
                                            </asp:Label>
                                             <asp:Label id="Label41" runat="server" Text='<%# Eval("id") %>' Visible="False"></asp:Label>                 
                                            </TD>
                                            </TR>
                                            <TR>
                                            <TD style="HEIGHT: 22px" width="35%">
                                            <asp:CheckBox id="CheckBox1" runat="server" Text='<%# Eval("da") %>'>
                                            </asp:CheckBox></TD>
                                            <TD style="HEIGHT: 22px" width="35%">
                                            <asp:CheckBox id="CheckBox2" runat="server" Text='<%# Eval("db") %>'>
                                            </asp:CheckBox></TD>
                                            </TR>                                             </TABLE>
                                            </ItemTemplate>
                                            </asp:TemplateField>
                                            </Columns>
                                                        <HeaderStyle Font-Size="12pt" HorizontalAlign="Left" />
                                                    </asp:GridView>
            </TD>
                
                </TR>
                </TABLE>
                </ItemTemplate>
                </asp:TemplateField>
                </Columns>
                            <HeaderStyle Font-Size="12pt" HorizontalAlign="Left" />
                        </asp:GridView>