[C#/WPF] DataTrigger 엘리먼트 사용하기

<Window
    x:Class="TestProject.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="리스트 박스 테스트"
    Width="600"
    Height="450"
    Loaded="mainWindow_Loaded">
    <Grid>
        <ListBox Name="listBox"
            Width="200"
            Height="300"
            SelectionMode="Single">
            <ListBox.ItemTemplate>
                <DataTemplate>
                    <StackPanel Orientation="Horizontal">
                        <Image Name="itemImage"
                            Margin="0 0 5 0"
                            Width="16"
                            Height="16"
                            VerticalAlignment="Center"
                            Stretch="None"
                            Source="{Binding Icon}" />
                        <TextBlock                            
                            VerticalAlignment="Center"
                            Text="{Binding Text}" />
                    </StackPanel>
                    <DataTemplate.Triggers>
                        <DataTrigger Binding="{Binding Icon}" Value="{x:Null}">
                            <Setter TargetName="itemImage" Property="Visibility" Value="Collapsed" />
                        </DataTrigger>
                    </DataTemplate.Triggers>
                </DataTemplate>            
            </ListBox.ItemTemplate>            
        </ListBox>
    </Grid>
</Window>