Hey, i have same exact code on the page, is not returning any value for the checkbox or returning null for  this

design page:

<IGGC:TemplateDataField Header-Text="" Width="30" Key="Asd">
<ItemTemplate>
<asp:CheckBox CssClass="tac" ID="CheckBox1" runat="server" AutoPostBack="True" />
</ItemTemplate>

checking this code:

CheckBox cb = (CheckBox)gr.Items.FindItemByKey("Asd").FindControl("CheckBox1");

this is returning null value, any idea or input please?