DomainEvents.cs

using System;
using ExtensionMethods;

namespace Events
{
    public static class DomainEvents
    {
        private static IEventHandlerResolver _handlerResolver;

        public static bool IsInitialised()
        {
            return _handlerResolver != null;
        }

        public static void Initialise( IEventHandlerResolver handlerResolver )
        {
            _handlerResolver = handlerResolver;
        }

        public static void Raise<T>( T args ) where T : IDomainEvent
        {
            EnsureInitialised();
            var eventHandlers = _handlerResolver.ResolveAll<T>();
            eventHandlers.Do( handler => handler.Handle( args ) );
        }

        public static void ResetHandlerResolver()
        {
            _handlerResolver = null;
        }

        private static void EnsureInitialised()
        {
            if( _handlerResolver == null )
            {
                throw new InvalidOperationException( "DomainEvents has not been initialised.  Initialise( IEventHandlerResolver ) must be called prior to registering callbacks or raising events." );
            }
        }
    }
}

IEventHandlerResolver.cs

using System.Collections.Generic;

namespace Events
{
    public interface IEventHandlerResolver
    {
        IEnumerable<IHandles<T>> ResolveAll<T>() where T : IDomainEvent;
    }
}