mef

I just started learning Prism and trying to use it with MEF in a test WPF application. Based on "WPF Hands-On Lab: Get Started with the Prism Library" example in the Prism4 documentation, in a test WPF project I renamed MainWindow class to Shell . My Bootstrapper class has the following code (also based on the Lab example): class Bootstrapper : MefBootstrapper { protected override DependencyObject CreateShell() { return new Shell(); } protected override void InitializeShell() { Application.Current.MainWindow = (Shell)this.Shell; Application.Current.MainWindow.Show(); } ... App.xaml.cs code:

I have an application with these step: startup application and ConfigureAggregateCatalog logon user to app download DLL MEF modules to directory called 'Modules' refresh directory catalog -- there is a problem I have empty directory 'Modules' after download dll i tried to load modules but without succes. There is an error on line where I called DirectoryCatalog.Refresh() System.ComponentModel.Composition.ChangeRejectedException was unhandled by user code Message=The composition remains unchanged. The changes were rejected because of the following error(s): The composition produced multiple

I have 2 MEF components. Let it be component A and component B. What I need is to be able to access a class from component B in component A without referencing to it. Then I would like to instantiate object of the class manually. Currently I see MEF allows instantiating an object automatically using [Import]. It uses interface which requires to be referenced to. Can I use data types from another assemblies without referencing to it? Is there such mechanism supported by MEF? There are a couple of ways to do this. First, you need to define a common interface that both assemblies understand. This

I've read that I should store an ObjectContext in HttpContext.Current in order to share my ObjectContext across different services/repositories that are called in a request. I'm wondering if it is safe to use an ObjectContext with the [ThreadStatic] attribute on a static class variable instead. Is that a safe thing to do? Is each request processed in its own thread? Heinzi No, there can be multiple requests in the same thread and, more importantly, one request can be processed in multiple threads . This is called thread agility , and you will run into problems when you store stuff in thread

(1) Using the code below I get exactly 2 items in my containers of one and the same exported plugin and I wonder why: (2) Additional question which I really cannot implement: How can I extend the framework to handle different plugin types (such as having several imports of different types, or one import that stores all plugins in a dynamic IEnumerable or so). I want to provide in my static wrapper class one generic method that returns the discovered plugin as a function of type and matching meta data. The exported plugin (which resides in a separate dll and whose location is pointed to when