There isn't an ItemsPanelSelector
(probably because it isn't a DataTemplate
) but you can bind it or use a Trigger
Binding
example
<ListBox ItemsPanel="{Binding RelativeSource={RelativeSource Self},
Path=Background,
Converter={StaticResource MyItemsPanelConverter}}">
Trigger
in Style
example
<ListBox ItemsSource="{Binding Source={x:Static Fonts.SystemFontFamilies}}">
<ListBox.Style>
<Style TargetType="ListBox">
<Setter Property="ItemsPanel">
<Setter.Value>
<ItemsPanelTemplate>
<StackPanel/>
</ItemsPanelTemplate>
</Setter.Value>
</Setter>
<Style.Triggers>
<!-- Your Trigger.. -->
<Trigger Property="Background" Value="Green">
<Setter Property="ItemsPanel">
<Setter.Value>
<ItemsPanelTemplate>
<WrapPanel/>
</ItemsPanelTemplate>
</Setter.Value>
</Setter>
</Trigger>
</Style.Triggers>
</Style>
</ListBox.Style>
</ListBox>