using System;

namespace DynamicPlayground
{
    class Program
    {
        /// <summary>
        /// When this is private it fails with:
        /// An unhandled exception of type 'Microsoft.CSharp.RuntimeBinder.RuntimeBinderException' occurred in System.Core.dll
        /// Additional information: 'DynamicPlayground.BaseHandler' does not contain a definition for 'When'
        /// </summary>
        private class TestHandler : BaseHandler
        {
            public bool Handled { get; private set; }

            public void When(TestEvent ev)
            {
                Handled = true;
            }
        }

        static void Main(string[] args)
        {

            var ev = new TestEvent();
            var sut = new TestHandler();
            sut.Handle(ev);

            Console.WriteLine("Handled: " + sut.Handled);

            Console.ReadKey();
        }
    }

    public abstract class BaseHandler
    {
        public void Handle(DomainEvent ev)
        {
            dynamic dynamicThis = (dynamic)this;
            dynamicThis.When((dynamic)ev);
        }
    }

    public class TestEvent : DomainEvent { }
    public abstract class DomainEvent { }

}