CheckBox inside ASP.Net GridView has value false even if Checked on Button Click

<asp:GridView ID="GridView1" runat="server"  >
                     <Columns>
                         <asp:TemplateField>
                            <ItemTemplate>
                                <asp:CheckBox ID="myCheckBox1"  runat="server"/>
                             </ItemTemplate>
                         </asp:TemplateField>
                         <asp:TemplateField HeaderText="Training Name" 
                              ItemStyle-HorizontalAlign="Center">
                              <ItemTemplate>
                              <asp:Label ID="lblTran" runat="server" Text='<%# Bind("Tran_Name") %>'>
                              </asp:Label>
                              </ItemTemplate>
                  <HeaderStyle Width="50px" />
               <ItemStyle HorizontalAlign="Center" />
             </asp:TemplateField>
     </Columns>
 </asp:GridView>

 always returns a false value even though if it is checked

  Dim myCheckBox As CheckBox = CType(row.FindControl("myCheckBox1"), CheckBox)
            If myCheckBox.Checked = True Then
           End if