Binding an action in an itemtemplate to an event

Question

I have listboxitems in a list-box that are being populated dynamically from an observable collection and I'm trying to use a Interaction trigger for the 'Selected' event of the listbox item to launch an action so that i can bind to the item coming from the observable collection.

The problem I'm having is that I can seem to access the 'Selected' event with the Event trigger.

Here's the code:

        <ListBox x:Name="AssocitedLayerListControl" Background="Transparent" BorderBrush="Transparent" ItemContainerStyle="{StaticResource ListBoxItemStyle}"
                ScrollViewer.VerticalScrollBarVisibility="Hidden" ScrollViewer.HorizontalScrollBarVisibility="Auto" 
                VerticalAlignment="Stretch" HorizontalAlignment="Stretch" Margin="10,0,10,0" Padding="0" Height="25" Width="Auto" >

            <!-- Attribute Table Item Template-->
            <ListBox.ItemTemplate>
                <DataTemplate>
                    <ContentControl>
                        <StackPanel Orientation="Horizontal" HorizontalAlignment="Center" VerticalAlignment="Center" Margin="0">
                            <TextBlock Text="{Binding Path=Key}"
                                    Foreground="#FFFFFFFF"
                                    FontSize="10" LineHeight="20"  
                                    HorizontalAlignment="Left" VerticalAlignment="Center"
                                    Margin="5,0,5,0" Padding="0" />
                            <Button BorderBrush="#FFFFFFFF" BorderThickness="1" Background="#FF000000"
                                HorizontalAlignment="Left" VerticalAlignment="Top"
                                Padding="1" Margin="0,1,0,1" Style="{StaticResource CloseItemStyle}">
                                <i:Interaction.Triggers>
                                    <i:EventTrigger EventName="Click">
                                        <actions:RemoveLayer LayerName="{Binding Path=Key}" TargetGraphicsLayer="{Binding Path=Value}" />
                                    </i:EventTrigger>
                                </i:Interaction.Triggers>
                            </Button>
                        </StackPanel>
                        <i:Interaction.Triggers>
                            <i:EventTrigger EventName="Selected" SourceObject="{Binding RelativeSource={RelativeSource Mode=TemplatedParent, AncestorType=ListBoxItem}}">
                                <actions:SetGraphicLayerInGrid LayerName="{Binding Path=Key}" TargetGraphicsLayer="{Binding Path=Value}" />
                            </i:EventTrigger>
                        </i:Interaction.Triggers>
                    </ContentControl>
                </DataTemplate>
            </ListBox.ItemTemplate>

            <ListBox.ItemsPanel>
                <ItemsPanelTemplate>
                    <StackPanel Orientation="Horizontal"/>
                </ItemsPanelTemplate>
            </ListBox.ItemsPanel>

        </ListBox>

Answer 1

Try to listen IsSelected property of ListBoxItem with DataTrigger :

xmlns:ei="http://schemas.microsoft.com/expression/2010/interactions"
...
<i:Interaction.Triggers>
    <ei:DataTrigger Binding="{Binding IsSelected, RelativeSource={RelativeSource FindAncestor, AncestorType=ListBoxItem}}" Value="True">
        <actions:SetGraphicLayerInGrid LayerName="{Binding Path=Key}" TargetGraphicsLayer="{Binding Path=Value}" />
    </ei:DataTrigger>
</i:Interaction.Triggers>