WP7 Itemtemplate click event fires on collapsed ExpanderView - windows-phone-7

Question

I am using the ExpanderView control available in the Silverlight Toolkit with some custom templates. It all works well, but when the ExpanderView is collapsed, and I click on the area below the Header where an item resides when the ExpanderView is expanded. The click event of that item fires.
How can i fix this? Should I somehow remove the tap commands or remove the ItemPanel when the ExpanderView is collapsed and add it again when it's being expanded?
<DataTemplate x:Key="CustomItemTemplate">
<Image delay:LowProfileImageLoader.UriSource="{Binding}" Width="156" Height="95" >
<i:Interaction.Triggers>
<i:EventTrigger EventName="Tap">
<cmd:EventToCommand Command="{Binding Storage.ImageTapCommand, Source={StaticResource Locator}}" CommandParameter="{Binding}" />
</i:EventTrigger>
</i:Interaction.Triggers>
</Image>
</DataTemplate>
<toolkit:ExpanderView Grid.Column="1" Header="{Binding}"
Expander="{Binding}" IsExpanded="{Binding IsExpanded, Mode=TwoWay}"
ItemsSource="{Binding Files}" HeaderTemplate="{StaticResource CustomHeaderTemplate}"
ExpanderTemplate="{StaticResource CustomExpanderTemplate}"
ItemTemplate="{StaticResource CustomItemTemplate}" >
<toolkit:ExpanderView.ItemsPanel>
<ItemsPanelTemplate>
<toolkit:WrapPanel />
</ItemsPanelTemplate>
</toolkit:ExpanderView.ItemsPanel>
</toolkit:ExpanderView>

Answer 1

You can change the IsHitTestVisible property of the root UIElement for each of your expander items every time the ExpanderView is expanded/collapsed, and also just after initially binding the ExpanderView (hooking up to ExpanderView.LayoutUpdated works fine for that purpose). Here's an example that fixed the issue for me:
private void FixExpanderItemsInteractivity(ExpanderView expanderView)
{
foreach (var item in expanderView.Items)
{
ContentPresenter contentPresenter = expanderView.ItemContainerGenerator.ContainerFromItem(item) as ContentPresenter;
if (contentPresenter != null)
{
UIElement expanderItemRootElement = VisualTreeHelper.GetChild(contentPresenter, 0) as UIElement;
if(expanderItemRootElement != null)
{
expanderItemRootElement.IsHitTestVisible = expanderView.IsExpanded;
}
}
}
}
private void Expander_Expanded(object sender, RoutedEventArgs e)
{
FixExpanderItemsInteractivity(sender as ExpanderView);
}
private void Expander_Collapsed(object sender, RoutedEventArgs e)
{
FixExpanderItemsInteractivity(sender as ExpanderView);
}
private void Expander_LayoutUpdated(object sender, EventArgs e)
{
FixExpanderItemsInteractivity(sender as ExpanderView);
}