title: Binding nested control using MVVM pattern
body: <p>I have a problem with binding nested control with my MVVM pattern. This is my XAML code:</p>
  
  <pre><code> &lt;ItemsControl Grid.Column="1" ItemsSource="{Binding NotificationContacts}"&gt;
              &lt;ItemsControl.ItemTemplate&gt;
                  &lt;DataTemplate&gt;
                      &lt;toolkit:Expander&gt;
                          &lt;toolkit:Expander.Header&gt;
                              &lt;Grid&gt;
                                  &lt;Grid.ColumnDefinitions&gt;
                                      &lt;ColumnDefinition Width="Auto" /&gt;
                                      &lt;ColumnDefinition Width="Auto" /&gt;
                                      &lt;ColumnDefinition Width="Auto" /&gt;
                                  &lt;/Grid.ColumnDefinitions&gt;
                                  &lt;TextBlock Text="{Binding ContactName}" Grid.Column="0" VerticalAlignment="Center"&gt;&lt;/TextBlock&gt;
                                  &lt;Image Source="Images/answer_ok.png" Grid.Column="1" Margin="15,0,15,0" Width="27" Height="27"&gt;&lt;/Image&gt;
                              &lt;/Grid&gt;
                          &lt;/toolkit:Expander.Header&gt;
                          &lt;toolkit:Expander.Content&gt;
                              &lt;ListBox Margin="30,10,0,10" ItemsSource="{Binding NotificationContacts.Messages"&gt;
                                  &lt;ListBox.ItemTemplate&gt;
                                      &lt;DataTemplate&gt;
                                          &lt;TextBlock Text="{Binding MessageName}"&gt;&lt;/TextBlock&gt;
                                      &lt;/DataTemplate&gt;
                                  &lt;/ListBox.ItemTemplate&gt;
                              &lt;/ListBox&gt;
                          &lt;/toolkit:Expander.Content&gt;
                      &lt;/toolkit:Expander&gt;
                  &lt;/DataTemplate&gt;
              &lt;/ItemsControl.ItemTemplate&gt;
          &lt;/ItemsControl&gt;
  </code></pre>
  
  <p>The problem is, that the listbox control located in ExpanderControl Data Template is not being  data bound. 
  Listbox control is populated by EntityCollection named 'Messages' which is contained in parent object 'NotificationContacts' that ItemsControl is databound with...</p>
  
  <p>Does anyone know how to resolve this issue ?</p>
  
  <p>Thanks in advance !!!</p>