title: Property change in Base ViewModel with prism
body: <p>I'm using prism to develop an android app.</p>
  
  <p>I'm trying to make a Base ViewModel. Inside this ViewModel I would like to set common properties to all my ViewModels.</p>
  
  <pre><code>  public class BaseViewModel : BindableBase
  {
      protected INavigationService _navigationService;
      protected IPageDialogService _dialogService;
  
      public BaseViewModel(INavigationService navigationService, IPageDialogService dialogService)
      {
          _navigationService = navigationService;
          _dialogService = dialogService;
      }
  
      private string _common;
      /// &lt;summary&gt;
      /// Common property
      /// &lt;/summary&gt;
      public string CommonProperty
      {
          get { return _common; }
          set
          {
              _common = value;
              SetProperty(ref _common, value);
          }
      }  
  }
  </code></pre>
  
  <p>My problem is: when I set the common property in the constructor, works fine.
  But when I´m setting the common property in <code>OnNavigatingTo</code> and using async, doesn´t work. The <code>SetProperty</code> is triggered when calling the <code>OnNavigatingTo</code>, but my binded label  with this common property doesn´t refresh the value.</p>
  
  <pre><code>namespace TaskMobile.ViewModels.Tasks
  {
  /// &lt;summary&gt;
  /// Specific view model
  /// &lt;/summary&gt;
  public class AssignedViewModel : BaseViewModel, INavigatingAware
  {
  
  
      public AssignedViewModel(INavigationService navigationService, IPageDialogService dialogService) : base(navigationService,dialogService)
      {
          CommonProperty= "Jorge Tinoco";  // This works
      }
  
      public async void OnNavigatingTo(NavigationParameters parameters)
      {
          try
          {
              Models.Vehicle Current = await App.SettingsInDb.CurrentVehicle();
              CommonProperty= Current.NameToShow; //This doesn´t works
          }
          catch (Exception e)
          {
              App.LogToDb.Error(e);
          }
      }
  }
  </code></pre>