title: Can't get ListBox and UpdateTarget to work
body: <p>Here are the relevant parts of the XAML file:</p>
  
  <pre><code>xmlns:local="clr-namespace:BindingTest"
  &lt;ListBox x:Name="myList"
           ItemsSource="{Binding Source={x:Static local:MyClass.Dic},
                                 Path=Keys,
                                 Mode=OneWay,
                                 UpdateSourceTrigger=Explicit}"&gt;
  &lt;/ListBox&gt;
  </code></pre>
  
  <p>MyClass is a public static class and Dic is a static public property, a  Dictionary.</p>
  
  <p>At a certain point I add items to the Dictionary and would like the ListBox to reflect the changes.<br>
  This is the code I thought about using but it doesn't work:</p>
  
  <pre><code>BindingExpression binding;
  binding = myList.GetBindingExpression(ListBox.ItemsSourceProperty);
  binding.UpdateTarget();
  </code></pre>
  
  <p>This code instead works:</p>
  
  <pre><code>myList.ItemsSource = null;
  myList.ItemsSource = MyClass.dic.Keys;
  </code></pre>
  
  <p>I would prefer to use UpdateTarget, but I can't get it to work.<br>
  What am I doing wrong?</p>