One thing I like about being on the MEF team, our product causes no shortage of controversy. :-)

Now to the question, what is the story on Prism and MEF? I am getting asked this now several times a day, more so than the IoC question. I am happy to say we’re working with p&p to come up with a good answer.

Glenn Block stirring up trouble with MEF again. MEF does seem to be a catch all technology though. I like it.

Prism should definitely be retooled to use it.

The patterns & practices team has just released Prism-v2.1, an updated version of the Composite Application Guidance for WPF & Silverlight, which has some breaking changes, mostly related to Silverlight 3 (from the “New in this release” article):

• All Visual Studio projects (Composite Application Library, reference implementation, and Quickstarts) were migrated to use Silverlight 3.
• TabRegionControlAdapter was modified to support binding in the TabItem’s control header in Silverlight 3.
• CreateXap.bat file was modified to search for Silverlight 3 assemblies if the Silverlight 2 reference assemblies cannot be found.
• Implemented the WeakEvent Pattern for the DelegateCommand’s and CompositeComand’s (more on this below).

If you were using Prism 2.0, either for WPF or Silverlight development, I would recommend you to start using this new version, as there is also an implementation “of the WeakEvent Pattern for the DelegateCommand’s and CompositeComand’s CanExecuteChanged event to fix a possible memory leak in the applications using the Composite Application Library commands”.

You can download the latest version of the guidance from here.

Kudos to the Prism team!!!

This is a very light Composite Framework. After dealing with CAB, everyone should have an appreciation for it. Prism should be strongly considered for anyone making any kind of WPF Application.