How can I get a vertical scrollbar in my ListBox?

Question

In the example below I have a ListBox with dozens of font names in it.

I would have thought it would automatically have a vertical scrollbar on it so that you can select ANY font, not just the first ones in the list, but it doesn't.

So I added a "ScrollViewer" and that puts a "scrollbar area" on the right but there is no scrollbar in the scrollbar area so that you can scroll (!).

Why isn't a scrollbar automatic and how do I force it to have a scrollbar?

<StackPanel Name="stack1">
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="2*"></RowDefinition>
            <RowDefinition Height="*"></RowDefinition>
        </Grid.RowDefinitions>
        <ScrollViewer>
            <ListBox Grid.Row="0" Name="lstFonts" Margin="3"  ItemsSource="{x:Static Fonts.SystemFontFamilies}"/>
        </ScrollViewer>
    </Grid>
</StackPanel>

Answer 1

XAML ListBox Scroller - Windows 10(UWP)

<Style TargetType="ListBox">
    <Setter Property="ScrollViewer.HorizontalScrollBarVisibility" Value="Visible"/>
    <Setter Property="ScrollViewer.VerticalScrollBarVisibility" Value="Visible"/>
</Style>