复选框不会更新

Question

我尝试更新目录数据库，根据在datagrid表CatalogueList中检查的行，将所有预订的书籍设置为n。
我已经添加了Response.Redirect作为测试，它什么也没做。我相信它没有看到是否已经检查了ItemCheckbox！

   Sub updateCat(sender as object, e as system.eventargs)

      dim item as datagriditem 

      For each item in CatalogueList.Items 

         Dim ItemCheckbox as CheckBox = CType(Item.cells(2).Controls(1), CheckBox)

         if ItemCheckbox.Checked = true Then

              ' was using the redirect as a text 
              ' Response.Redirect("test.aspx")

                dim grabid as string = "Select id where cataloguename = '{0}'"
                dim mydata as datatable = Database.SelectRows(String.Format(grabid,item.cells(1).Text))

                   if mydata.Rows.Count > 0 then 
                       dim updatePreorder as string = "Update titles_catalogue set preorder = 'n' where id = '{0}'"
                       Database.InsertRecord(String.Format(updatePreorder, mydata.rows(0)("id")))
                   end if 
          end if 
      NEXT      
   End Sub



 <asp:DataGrid id="CatalogueList" runat="server"
   <Columns>
                    <asp:BoundColumn HeaderText="ID" 
                          ReadOnly="true" 
                          DataField="id"
                          Visible="false"/>

                    <asp:HyperLinkColumn HeaderText="Catalogue Name" 
                          DataNavigateUrlFormatString="view_catalogue.aspx?id={0}"
                          DataTextFormatString="{0}"
                          DataNavigateUrlField="id"
                          DataTextField="name"/>

                   <asp:TemplateColumn >
                      <HeaderTemplate>
                       <asp:CheckBox id="chkHeader" runat="server" />
                      </HeaderTemplate>
                    <ItemTemplate>
                       <asp:CheckBox id="chkRow" runat="server" />
                   </ItemTemplate>

                  </asp:TemplateColumn>

   </columns>
 </asp:DataGrid>