title: Would setting a collection to null after assigning it to an itemssource clear up resources?
body: <p>I was doing some performance optimization inside my app and there were a lot of places where I'm assigning a collection to the itemssource property of a listbox. When I assign the collection to the listbox is the original collection disposed from memory. If not, by setting it to null will it mark the collection for garbage collection?</p>
  
  <p>For example:</p>
  
  <pre><code>void myWebServiceCompleted(object sender, List&lt;Item&gt; itemList)
  {
      ItemListBox.ItemsSource = itemList;
      //Would setting itemList = null clear up resources?
  }
  </code></pre>
  
  <p>I was just concerned because this type of assignment is made in multiple places in the app and if the above is true that means twice the memory.</p>