EventDispatcher.cs

public class EventDispatcher : IDispatchEvents
{
	private readonly IDictionary<Type, Action<IDomainEvent>> handlers = new Dictionary<Type, Action<IDomainEvent>>();

	public virtual void Register<TEvent>(Action<TEvent> handler)
		where TEvent : class, IDomainEvent
	{
                // re-wrap delegate
		this.handlers[typeof(TEvent)] = @event => handler(@event as TEvent);
	}

	public virtual void Dispatch(IDomainEvent message)
	{
		Action<IDomainEvent> handler;

		if (!this.handlers.TryGetValue(message.GetType(), out handler))
			throw new EventNotRegisteredException(message.GetType());

		handler(message);
	}
}