title: Filter a collection multiple times using ICollectionView
body: <p>I'm trying to filter an ObservableCollection that is displayed in a DataGrid.
  This works great the first time, but when I try to filter again, it uses the sourcecollection instead of the filtered result.
  Short code example:</p>
  
  <pre><code>ICollectionView view = CollectionViewSource.GetDefaultView(myCollection);
  view.Filter = delegate(object item){
    User user = item as User;
    if(user != null &amp;&amp; user.Name.ToLower().Contains(textbox.Text.ToLower())) return true;
    return false;
  };
  </code></pre>
  
  <p>So what I want to do is filter only the items that are shown in my DataGrid, and NOT the entire collection (of course the first time that the filter is used, it will use the entire collection).</p>