单击Longlistselector中的Empty Jumplist

Question

我需要在用户点击空跳转列表时捕获事件，但我已经尝试了点击事件，或者将跳转列表的数据模板放在按钮中并尝试点击事件，但它们都没有工作。看起来我无法与空白部分互动。 Longlistselector仅提供2个方法：JumplistOpening和JumplistClosed。那么如何点击灰色跳转列表？

 <phone:LongListSelector x:Name="llsMainSong"                                                
       IsGroupingEnabled="True" HideEmptyGroups="True"                                                
       JumpListStyle="{StaticResource JumpListStyle}"
       GroupHeaderTemplate="{StaticResource GroupHeaderTemplate}"
       ItemsSource="{Binding GroupedMainSongList}">
     .........
 </phone:LongListSelector>


 <Style x:Key="JumpListStyle" TargetType="phone:LongListSelector">
        <Setter Property="GridCellSize"  Value="230,113"/>
        <Setter Property="LayoutMode" Value="Grid" />
        <Setter Property="ItemTemplate">
            <Setter.Value>
                <DataTemplate>
                    <Button Background="LightGray" Height="113" Margin="6" Click="Button_Click">
                        <TextBlock Text="{Binding Title}" FontSize="28" Padding="6" VerticalAlignment="Center"
                                   Style="{StaticResource HelveBoldWhite}"/>
                    </Button>
                </DataTemplate>
            </Setter.Value>
        </Setter>
    </Style>

  private void Button_Click(object sender, RoutedEventArgs e)
    {
        Debug.WriteLine("click");  
        // ^ only jumplist which bind to group has data fired the event.         
    }