<UserControl x:Class="UI.MainView"
  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"
  xmlns:local="clr-namespace:UI"
  xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
  xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
  mc:Ignorable="d"
  d:DataContext="{d:DesignInstance Type={x:Type local:MainViewModel}, IsDesignTimeCreatable=False}"
			 HorizontalAlignment="Left"
			 VerticalAlignment="Top"
			 HorizontalContentAlignment="Stretch" 
			 VerticalContentAlignment="Stretch">
	<Canvas HorizontalAlignment="Stretch" VerticalAlignment="Stretch">
		<Button HorizontalAlignment="Stretch" HorizontalContentAlignment="Stretch" >
			<Button.Command>
				<local:CommandProxy/>
			</Button.Command>
			Test button
		</Button>
	</Canvas>
</UserControl>

	public class CommandProxy : ***DependencyObject***, ICommand
	{
		public bool CanExecute(object parameter) => true;
		public void Execute(object parameter)
		{
			UnityEngine.Debug.Log("CommandProxy.Execute");
		}
		public event EventHandler CanExecuteChanged;
	}