MEF. How to clean up the default container?

Question

I'm trying to implement Logout operation in my Silverlight client.

During Login operation, MEF initializes DefaultContainer with instances of the [Export]-ed singleton classes, which contain user-specific information (like password).

Is there a way, to re-initialize/reset/drop MEF infrastructure/DefaultContainer like it was never initialized?

I'd like to navigate to Login page again after user successfully performs Logout operation...

Answer 1

It is not possible to reinitialize the CompositionHost container. Once it has been Initialized or created by default it can't be changed.

You could however create an AggregateCatalog and use a TypeCatalog with the singleton as the only type and remove this from the aggregate when its no longer needed.

This doesn't change the fact that once a 'part' is created by MEF it is available to satisfy any other [Import] which needs it.

From MSDN:

Parts created by the default container to fill imports will be retained by the Managed Extensibility Framework (MEF) until the application shuts down. Long-running applications should use ExportFactory< T > to manage the life cycles of their parts.