private void Model_MessageSummaryReceived(object sender, MessageSummaryArgs e)
 {
     btnMessageSummary.Dispatcher.Invoke(new Action(() =>
     {
         btnMessageSummary.GetBindingExpression(Button.ContentProperty).UpdateTarget();
         btnMessageSummary.GetBindingExpression(Button.IsEnabledProperty).UpdateTarget();
     }));
 }
 private void OnMessageSummaryReceived(MessageSummaryArgs args)
 {
     var handler = MessageSummaryReceived;
     if (handler != null)
         handler(this, args);
 }