隐藏代码隐藏文件中的模板元素

Question

我有一个LongListHeaderTemplate，它由一个列表和一个按钮组成。您将看到它们如何在下面的代码中分发。我的问题是我需要在代码隐藏文件中隐藏按钮。我怎么能这样做？！ XAML：

 <toolkit:LongListSelector Grid.Row="1" ListHeader="{Binding EpsLaterItems}" IsFlatList="True" ItemsSource="{Binding EpsItems}" x:Name="EPS" SelectionChanged="EPS_SelectionChanged_1">
                    <toolkit:LongListSelector.ItemTemplate>
                        <DataTemplate>
                            <StackPanel Orientation="Horizontal">
                                <Image Source="{Binding ImageUrl, Converter={StaticResource BmpConverter}}" Width="100" Height="100" VerticalAlignment="Top" Margin="0,10,18,0"/>
                                <StackPanel Margin="0,0,0,20" Width="300">
                                    <TextBlock Text="{Binding Date, ConverterCulture=ru-RU, StringFormat=f}" 
                                       FontSize="22" FontWeight="Bold" Foreground="#FFD65B2D" />
                                    <TextBlock Text="{Binding Title}" TextWrapping="Wrap" FontSize="22" Foreground="Aqua" />
                                </StackPanel>
                            </StackPanel>
                        </DataTemplate>
                    </toolkit:LongListSelector.ItemTemplate>
                    <toolkit:LongListSelector.ListHeaderTemplate>
                        <DataTemplate>
                            <StackPanel>
                                <ListBox x:Name="listbox1" ItemsSource="{Binding}" ScrollViewer.VerticalScrollBarVisibility="Disabled" >
                                    <ListBox.ItemTemplate>
                                        <DataTemplate>
                                            <StackPanel Orientation="Horizontal">
                                                <Image Source="{Binding ImageUrl, Converter={StaticResource BmpConverter}}" Width="100" Height="100" VerticalAlignment="Top" Margin="0,10,18,0"/>
                                                <StackPanel Margin="0,0,0,20" Width="300">
                                                    <TextBlock Text="{Binding Date, ConverterCulture=ru-RU, StringFormat=f}" 
                                       FontSize="22" FontWeight="Bold" Foreground="#FFD65B2D" />
                                                    <TextBlock Text="{Binding Title}" TextWrapping="Wrap" FontSize="22" Foreground="Aqua" />
                                                </StackPanel>
                                            </StackPanel>
                                        </DataTemplate>
                                    </ListBox.ItemTemplate>
                                </ListBox>
                                <Button x:Name="footerEpsLater" Content="more..." 
                    FontSize="30" Foreground="SteelBlue" Style="{StaticResource StyleForButton}" BorderBrush="#FFFF2121"/>
                            </StackPanel>
                        </DataTemplate>
                    </toolkit:LongListSelector.ListHeaderTemplate>
                    <toolkit:LongListSelector.ListFooterTemplate>
                        <DataTemplate>
                            <Button Content="more..." FontSize="30" Foreground="SteelBlue" Click="footerEPS_Click_1" Style="{StaticResource StyleForButton}"/>
                        </DataTemplate>
                    </toolkit:LongListSelector.ListFooterTemplate>
                </toolkit:LongListSelector>

如果我喜欢这个footerEpsLater.Visibility = Visibility.Collapsed;我收到错误：footerEpsLater在此上下文中不存在