Avalonia/samples/ControlCatalog/Pages/ItemsRepeaterPage.xaml

<UserControl xmlns="https://github.com/avaloniaui"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             x:Class="ControlCatalog.Pages.ItemsRepeaterPage">
  <DockPanel>
    <StackPanel DockPanel.Dock="Top" Spacing="4" Margin="0 0 0 16">
      <TextBlock Classes="h1">ItemsRepeater</TextBlock>
      <TextBlock Classes="h2">A data-driven collection control that incorporates a flexible layout system, custom views, and virtualization.</TextBlock>
    </StackPanel>
    <StackPanel DockPanel.Dock="Right" Margin="8 0">
      <ComboBox SelectedIndex="0" SelectionChanged="LayoutChanged">
        <ComboBoxItem>Stack - Vertical</ComboBoxItem>
        <ComboBoxItem>Stack - Horizontal</ComboBoxItem>
        <ComboBoxItem>UniformGrid - Vertical</ComboBoxItem>
        <ComboBoxItem>UniformGrid - Horizontal</ComboBoxItem>
      </ComboBox>
    </StackPanel>
    <Border BorderThickness="1" BorderBrush="{DynamicResource ThemeBorderMidBrush}" Margin="0 0 0 16">
      <ScrollViewer Name="scroller"
                    HorizontalScrollBarVisibility="Auto"
                    VerticalScrollBarVisibility="Auto">
        <ItemsRepeater Name="repeater" Items="{Binding}"/>
      </ScrollViewer>
    </Border>
  </DockPanel>
</UserControl>