<Window x:Class="IsItemsHostSample.Window1"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:sys="clr-namespace:System;assembly=mscorlib" 
    Title="IsItemsHostSample">
  <Window.Resources>
    <x:ArrayExtension Type="{x:Type sys:String}"  x:Key="items">
      <sys:String>one for the money,</sys:String>
      <sys:String>two for show,</sys:String>
      <sys:String>three to get ready,</sys:String>
      <sys:String>four to go!</sys:String>
    </x:ArrayExtension>
  </Window.Resources>
  <ListBox ItemsSource="{StaticResource items}" Width="120" Height="67">
    <ListBox.Template>
      <ControlTemplate TargetType="{x:Type ListBox}">
        <Border BorderThickness="1" BorderBrush="Black" CornerRadius="10">
          <ScrollViewer>
            <ScrollViewer.Clip>
              <RectangleGeometry Rect="0, 0, 118, 65"></RectangleGeometry>
            </ScrollViewer.Clip>
            <VirtualizingStackPanel IsItemsHost="True" />
          </ScrollViewer>
        </Border>
      </ControlTemplate>
    </ListBox.Template>
  </ListBox>
</Window>
