Basic concept of importing DLLs. Does this make sense?

Jun 29, 2010 at 7:10 PM
Im new to the IoC/DI concept.. I have a good MEF demo which shows how you can make a program that accepts .DLLs that implement a certain interface and so you can have different filters on a picture http://www.wintellect.com/CS/blogs/jprosise/archive/2010/01/04/silverlight-4-s-new-managed-extensibility-framework.aspx So my case is a WCF service which needs to accept requests (UserID,AppId) and return back a Collection of Warnings/Notifications... So the question is where should the logic exist? Should it be in each individual app? Or should it be in the notification WCF service OR Is there a way my notification service can IMPORT each .DLL that implements a INotification interface so I loop through each .DLL and treat thme all the same and get the information I need.. and this way I tell the coders for app A, B and C.. hey guys.. here is the interface.. just create a class library that implements it and my WCF service can do the rest.. Does this make sense? Is this hard? Whats the best way to gather these .DLLs? Is this wha t'Unity' is for.. I know MEF has the IMPORT/EXPORT/COMPOSE concepts... is unity basically the same thing?? it will import the DLLs and let me treat them all in one way.