Avalonia/samples/ControlCatalog/MainView.xaml

<UserControl x:Class="ControlCatalog.MainView"
             xmlns="https://github.com/avaloniaui"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:controls="using:ControlSamples"
             xmlns:models="using:ControlCatalog.Models"
             xmlns:pages="using:ControlCatalog.Pages"
             xmlns:viewModels="using:ControlCatalog.ViewModels"
             x:DataType="viewModels:MainWindowViewModel">
  <Image x:Name="PART_Image" />
</UserControl>