public class ViewModelInitializer<TViewModel,TModel> where TViewModel : IViewModel<TModel>
{
    private Func<TViewModel> _viewModelFactory;
 
    public ViewModelInitializer(Func<TViewModel> viewModelFactory)
    {
        _viewModelFactory = viewModelFactory;
    }
 
    public void Initialize(FrameworkElement view, TModel model)

// Below RecentlyUsedTrackerConfiguration provides configuration information through property exports. MEF pulls on the property getters and exports that info. 
// If the part needs to be data drvien, you can still access a service behind the scenes in the getter (or the constructor) to get the info.
 
public class RecentlyUsedTrackerConfiguration
{
  public RecentlyUsedTrackerConfiguration()
  {
     //set values here
  }

public static class AsyncTestExtensions
{
    public static void EnqueueUntilLoaded(this SilverlightTest test, FrameworkElement element, params Action[] actions)
    {
        var isLoaded = false;
        element.Loaded += (s, e) => isLoaded = true;
        test.EnqueueConditional(() => isLoaded);
        test.EnqueueCallback(actions);
        test.EnqueueTestComplete();
    }

namespace System.ComponentModel.Composition.Hosting
{
    public class DeploymentCatalog : ComposablePartCatalog, INotifyComposablePartCatalogChanged
    {
        public DeploymentCatalog();
        public DeploymentCatalog(string uri);
        public DeploymentCatalog(Uri uri);
        public override IQueryable<ComposablePartDefinition> Parts { get; }
        public Uri Uri { get; }

using System.ComponentModel.Composition;
using Microsoft.Practices.Composite.Events;
 
//this version uses a static backing field so that the instance is automatically shared across all containers.
public class EventAggregatorPart
{
    private static IEventAggregator _eventAggregator;
 
    static EventAggregatorPart()
    {   

 
var catalog = new DirectoryCatalog(@".\");
var rootCatalog = new FilteredCatalog(catalog, cpd=>!cpd.Metadata.ContainsKey("Scope") || (cpd.Metadata.ContainsKey("Scope") && cpd.Metadata["Scope"].Equals("Root"));
var childCatalog = new FilteredCatalog(catalog, cpd=>cpd.Metadata.ContainsKey("Scope") && cpd.Metadata["Scope"].Equals("Child"));
var rootContainer = new CompositionContainer(rootCatalog);
var childContainer = new CompositionContainer(childCatalog, rootContainer);
 

using System;
using System.Net;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Ink;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;

Imports System.ComponentModel.Composition
Imports System.ComponentModel.Composition.Hosting
Imports System.ComponentModel.Composition.Deployment
 
Namespace DeploymentCatalogDesignVB
    Namespace Setting_up_the_host_to_download_catalogs
        Public Class App
            Inherits Application
 
            Public Sub Initialize()

/*
 
Sample below illustates export inheritance where the base export provides metadata that is overriden by the inheritor
using a custom metadata attribute. 
 
In this case OverridingExtension implements IExtension but then explicitly overrides the base and provides new metadata. 
 
The result is a single export rather than two exports.
 
Notice the inheritor is using an InheritedExport attribute + a custom metadata attribute to override rather than using a custom InheritedExport. 

/*

Sample below illustatres export inheritance where the base export provides metadata that is overriden by the inheritor
using an InheritedExport and ExportMetadata attributes. 

In this case OverridingExtension implements IExtension but then explicitly overrides the base and provides new metadata. 

The result is a single export rather than two exports.

*/

//Design time VM
 
        [Export]
        public ContactVM GetViewModel()
        {
            var contact = new Contact()
            {
                FirstName = "John",
                LastName = "Doe",
                City = "Design time",

namespace Microsoft.ComponentModel.Composition.Packaging
{
    public static class ContainerBuilder
    {
        private static PackageCatalog _packageCatalog;
        private static CompositionContainer _container;
        private static object _lock = new Object();
 
        public static CompositionContainer GetContainer()
        {

using System;
using System.ComponentModel.Composition.Primitives;
using System.Collections.Generic;
using System.ComponentModel.Composition.ReflectionModel;
using System.ComponentModel.Composition;
using System.Reflection;
using System.Linq;
using System.ComponentModel.Composition.Hosting;
using System.Collections;

namespace ExtensibleGrid.GridLibrary
{
    public class ExtensibleDataGrid : DataGrid
    {
        private ConfigDialog dialog { get; set; }
        private IEnumerable<ExtensionItem> extensionItems;
    
        public override void OnApplyTemplate()
        {
            dialog = new ConfigDialog();

Binder = ViewBinder.For(this, vm).
    Value(p => p.FirstName).
    Value(p => p.Address).
    AddBinder(new ValueBinder<ContactViewModel>(this.OnMailingList, vm)).
    List(p => p.Cities).
    Action(p => vm.Save()).
    Template<City>("City", t => t.Value(p => p.CityName));
 

public class StringHelper
{
    public static string ToString(object instance)
    {
        var properties = TypeDescriptor.GetProperties(instance);
        StringBuilder output = new StringBuilder();
        foreach (PropertyDescriptor property in properties)
        {
            output.Append(string.Format("{0} - {1}\r\n", property.Name, property.GetValue(instance)));
        }

 
 
public class CSLExportProvider : ExportProvider
{
    private IServiceLocator serviceLocator;
    private IDictionary<string, Type> contractMapping;
    
    public CSLExportProvider(IServiceLocator serviceLocator)
    {
        this.contractMapping = new Dictionary<string, Type>();

   /// <summary>
   /// Summary description for MvvmLightExtensionsFixture
   /// </summary>
   [TestClass]
   public class When_Subscribe_is_called_on_SingleSubscriber : MessengerContext
   {
       [TestMethod]
       public void then_message1_is_registered()
       {
           _mock.Verify(c =>c.Register<Message1>(_singleSubscriber, _singleSubscriber.Subscribe));            

[TestClass]
public class MefEventAggregatorTestFixture
{
    [TestMethod]
    public void Subscriber_is_invoked_when_publisher_raises_event()
    {
       var catalog = new InterceptingCatalog(
            new TypeCatalog(typeof(EventAggregator), typeof (FakePublisher), typeof (MockSubscriber))
            );
        var container = new CompositionContainer(catalog);

//See Wes Haggard's updated implementation here: http://codepaste.net/ktdgoh
 
//Adapting collection is a generic collection that allows you to adapt the contents using your own custom logic.
 
    public abstract class AdaptingCollection<T> : 
        ICollection<T>
    {
        private readonly List<T> _innerCollection = new List<T>();
        private List<T> _adaptedCollection;
        private bool _changed=true;

    public class GenericCatalog : ComposablePartCatalog, INotifyComposablePartCatalogChanged
    {
        private ComposablePartCatalog _decoratedCatalog;
        private AggregateCatalog _catalog = new AggregateCatalog();
        private IDictionary<string, Type> _closedTypes = new Dictionary<string, Type>();
        private IDictionary<string, Type> _genericTypes = new Dictionary<string, Type>();
 
        public GenericCatalog(ComposablePartCatalog catalog)
        {
            _decoratedCatalog = catalog;