DefaultView.cs

using System;
using System.Numerics;
using Windows.ApplicationModel.Core;
using Windows.UI;
using Windows.UI.Composition;
using Windows.UI.Core;

namespace DemoComposition
{
    class DefaultView : IFrameworkView, IFrameworkViewSource
    {
        Compositor _compositor = default(Compositor);
        CompositionTarget _target = default(CompositionTarget);

        static void Main()
        {
            CoreApplication.Run(new DefaultView());
        }

        public IFrameworkView CreateView()
        {
            return this;
        }

        public void Run()
        {
            CoreWindow window = CoreWindow.GetForCurrentThread();
            window.Activate();
            window.Dispatcher.ProcessEvents(CoreProcessEventsOption.ProcessUntilQuit);
        }

        public void SetWindow(CoreWindow window)
        {
            _compositor = new Compositor();
            _target = _compositor.CreateTargetForCurrentView();

            ContainerVisual root = _compositor.CreateContainerVisual();
            _target.Root = root;

            // a kind of magic to add here
        }

        public void Initialize(CoreApplicationView applicationView) { }
        public void Load(string entryPoint) { }
        public void Uninitialize() { }
    }
}