[Export(typeof(SampleView))]
  public partial class SampleView : UserControl
  {
      [ImportingConstructor]
      public SampleView([Import] IEventAggregator eventAggregator)
      {
          InitializeComponent();

          eventAggregator.
              GetEvent<CompositePresentationEvent<ItemSelectedEvent>>().
                  Subscribe(OnItemSelectedReceived);
      } 

      public void ItemSelectedReceived(ItemSelectedEvent item)
      {
         // wykonaj jak czynno z tym elementem
      }
  }
