Custom NotFound Controller

I choose the Handler for the Function property. This way I was able to use it in the NotFoundHandler, in  the ControllerFactoryWrapper and in the ActionInvokerWrapper and did not have to change the visibility of the latter two.

You can configure your own controller in Global.asax
NotFoundMvc.NotFoundHandler.CreateCustomNotFoundController =
requestContext =>
{
//some sort of logic...
return new MyCustomNotFoundController(requestContext);
//or return null for default functionality
};