using System;
using System.Collections.Generic;
using System.ComponentModel.Composition; 
using System.ComponentModel.Composition.Hosting;
using System.Reflection; 

namespace HelloWorld
{
    class Program
    {
        [Import]
        public string Message { get; set; }

        public class SimpleHello
        {
            [Export]
            public string Message
            {
                get { return "Hello World!"; }
            }
        }

        public void Run()
        {
            var catalog=new AttributedAssemblyPartCatalog(Assembly.GetExecutingAssembly());
            var container=new CompositionContainer(catalog.CreateResolver());
            container.AddPart(this);
            container.Compose();

            Console.WriteLine(Message);
            Console.ReadKey();
        }
        static void Main(string[] args)
        {
            Program pg = new Program();
            pg.Run();
        }
    }
}