title: CollectionViewSource.GetDefaultView is not in Silverlight 3! What's the work-around?
body: <p>The <code>CollectionViewSource.GetDefaultView()</code> method is <em>not</em> in Silverlight 3. In WPF I have this extension method:</p>
  
  <pre><code>public static void SetActiveViewModel&lt;ViewModelType&gt;(this ViewModelBase viewModel,
      ViewModelType collectionItem,
      ObservableCollection&lt;ViewModelType&gt; collection) where ViewModelType : ViewModelBase
  {
      Debug.Assert(collection.Contains(collectionItem));
      ICollectionView collectionView = CollectionViewSource.GetDefaultView(collection);
      if(collectionView != null) collectionView.MoveCurrentTo(collectionItem);
  }
  </code></pre>
  
  <p>How can this be written in Silverlight 3?</p>