HierarchicalDataTemplate.aspx

<HierarchicalDataTemplate x:Key="CheckBoxTreeViewItemTemplate" ItemsSource="{Binding Items, Mode=OneWay}" >
        <StackPanel Orientation="Horizontal">
            <Image Margin="2,0" Source="{Binding ImageSource, Mode=TwoWay}" />
                     <CheckBox Focusable="False" IsChecked="{Binding IsChecked}" VerticalAlignment="Center"
                                    <span style="background-color: #ffff00;">Command="{Binding CheckedEvent}"</span>/>
                     <ContentPresenter Content="{Binding Text, Mode=TwoWay}" Margin="2,0" />
        </StackPanel>
    </HierarchicalDataTemplate>