</UserControl.Resources>
    <DataTemplate x:Key="ItemTemplate">
        <StackPanel>
            <TextBlock Text="{Binding RandomValues}"/>
        </StackPanel>
    </DataTemplate>
    <ItemsPanelTemplate x:Key="UniformGridPanel">
        <UniformGrid Rows="1" HorizontalAlignment="Center"/>
    </ItemsPanelTemplate>
</UserControl.Resources>

<ListBox HorizontalAlignment="Left" Height="100" VerticalAlignment="Top" Width="Auto" DataContext="{Binding}" ItemTemplate="{DynamicResource ItemTemplate}" ItemsSource="{Binding Collection}" ItemsPanel="{DynamicResource UniformGridPanel}" Style="{DynamicResource ListBoxStyle}"/>