A very basic event dispatcher

EventDispatcher.cs

public class EventDispatcher
{
  private EventHandlerRegistry _registry;

	public EventDispatcher(EventHandlerRegistry reg)
	{
		_registry = reg;
	}
	
	public void Dispatch(object e)
	{
		var handlers = _registry.HandlersForMessageType(e.GetType());
		foreach(var handler in handlers)
			((dynamic)handler).Handle((dynamic) e);
	}
}

EventHandlerRegistry.cs

public class EventHandlerRegistry
{
   private readonly Dictionary<Type, List<object>> _eventHandlers;

  public EventHandlerRegistry()
	{
		_eventHandlers = new Dictionary<Type, List<object>>();
	}
	
	public void RegisterByConvention(object handler)
	{
		var handlerType = handler.GetType();
		
		var handlerInterfaces = handlerType.GetInterfaces().Where(i => i.IsGenericType && i.GetGenericTypeDefinition() == typeof(IConsume<>)).ToArray();
		
		foreach (var messageType in handlerInterfaces.Select(i => i.GetGenericArguments()[0]))
        {
            AddHandlerToRegistry(messageType, handler);
        }
	}
	
	public void AddHandlerToRegistry(Type messageType, object handler)
	{
		List<Object> handlerList;
		var hasHandlerList = _eventHandlers.TryGetValue(messageType, out handlerList);
	
		if (!hasHandlerList)
		{
			handlerList = new List<Object>();
			_eventHandlers.Add(messageType, handlerList);
		}
	
		handlerList.Add(handler);
	}
	
	public IEnumerable<object> HandlersForMessageType(Type messageType)
	{
		List<object> handlerList;
		var hasHandlerList = _eventHandlers.TryGetValue(messageType, out handlerList);
	
		return hasHandlerList ? handlerList : new List<object>();
	}
}

IConsume.cs

public interface IConsume<in TMessage>
{
    void Handle(TMessage message);
}

Sample.cs

void Main()
{
  var reg = new EventHandlerRegistry();
	var dispatcher = new EventDispatcher(reg);
	
	var handler = new SomeEventHandler();
	
	//reg.AddHandlerToRegistry(typeof(SomeEvent), handler);
	reg.RegisterByConvention(handler);
	
	var e = new SomeEvent() { EventText = "Woftam" };
	
	dispatcher.Dispatch(e);
		
	Console.ReadLine();
}

public class SomeEvent
{
	public string EventText {get;set;}
}

public class SomeEventHandler : IConsume<SomeEvent>
{
	public void Handle(SomeEvent e)
	{
		Console.WriteLine (e.EventText);
	}
}