title: Receive Notifications from Child ViewModels
body: <p>I might be missing something simple, so bear with me.
  I have a ViewModel that contains the following:</p>
  
  <pre><code>public ObservableCollection&lt;Person&gt; PersonCollection
  {
      get { return personCollection; }
      set
      {
          if (personCollection != value)
          {
              personCollection = value;
              RaisePropertyChanged("PersonCollection");
          }
      }
  }
  </code></pre>
  
  <p>Then in another ViewModel I have:</p>
  
  <pre><code>public ObservableCollection&lt;Person&gt; PersonCollection
  {
      get
      {
          PersonViewModel vm = (App.Current.Resources["Locator"] as ViewModelLocator).PersonViewModel;
          return vm.PersonCollection;
      }
  }
  
  public PersonViewModel PersonViewModel
  {
      get
      {
          return ((App.Current.Resources["Locator"] as ViewModelLocator).PersonViewModel)
      }
  }
  </code></pre>
  
  <p>In my XAML if I bind to <code>PersonCollection</code> then updates don't happen on my view, but if I bind to <code>PersonViewModel.PersonCollection</code> it does. so is this the "proper" way to do it or is there a way for the view to detect the notifications using the first approach?</p>