title: ChangePropertyAction to modify Visibility not working in ListBoxItem DataTemplate
body: <p>I am trying to change the visibility of a control in a ListBoxItem template (based on it beeing selected in the parent listbox) through a ChangePropertyAction but the code below does not work. I tried fiddling around with setting the TargetName on the trigger or setting the default visibility of the control through a style. I debugged the Binding through a DebugConvert and checked that the IsSelected is correctly set to true but it still does not work. Can anybody explain to me why this is not working and how I can fix this?</p>
  
  <pre><code>&lt;ListBox.ItemTemplate&gt;
                      &lt;DataTemplate&gt;
                          &lt;StackPanel&gt;
                              &lt;Grid&gt;
                                  &lt;Grid.ColumnDefinitions&gt;
                                      &lt;ColumnDefinition/&gt;
                                      &lt;ColumnDefinition/&gt;
                                      &lt;ColumnDefinition/&gt;
                                  &lt;/Grid.ColumnDefinitions&gt;
                                  &lt;TextBlock Text="{Binding PersonalData.LastName}" FontSize="20" FontWeight="Bold"  Grid.Column="0"/&gt;
                                  &lt;TextBlock FontSize="20" Text="{Binding PersonalData.FirstName}" Grid.Column="1" /&gt;
                                  &lt;StackPanel x:Name="buttonStackPanel" Orientation="Horizontal" Grid.Column="2" Visibility="Collapsed"&gt;
                                      &lt;Interactivity:Interaction.Triggers&gt;
                                          &lt;ei:DataTrigger Binding="{Binding RelativeSource={RelativeSource AncestorType={x:Type ListBoxItem}, Mode=FindAncestor}, Path=IsSelected, Converter={StaticResource DebugConverter}}"&gt;
                                              &lt;ei:ChangePropertyAction PropertyName="Visibility"&gt;
                                                  &lt;ei:ChangePropertyAction.Value&gt;
                                                      &lt;Visibility&gt;Visible&lt;/Visibility&gt;
                                                  &lt;/ei:ChangePropertyAction.Value&gt;
                                              &lt;/ei:ChangePropertyAction&gt;
                                          &lt;/ei:DataTrigger&gt;
                                      &lt;/Interactivity:Interaction.Triggers&gt;
                                      &lt;Button Content="Do Something"&gt;&lt;/Button&gt;
                                  &lt;/StackPanel&gt;
                              &lt;/Grid&gt;
  [...]
  </code></pre>