private void LabelMouseDown(object sender, MouseButtonEventArgs e)
        {
            var lb = (sender as LabelUpDown);

            if (lb != _currentLabel)
            {
                lb.ShowArrow();
                _currentLabel.HideArrow();
                _currentLabel = lb;
            }
            string propertyName = _currentLabel.LabelText;

            if (propertyName == "Department")
            {
                propertyName = "CurrentDepartment";
            }
            ArrowType arrowType = _currentLabel.ArrowType;

            _data.OrderEmployees(propertyName, arrowType);
        }
 private void PageListEmployees_Loaded(object sender, RoutedEventArgs e)
 {
     _labels.ForEach(x => x.HideArrow());
     lbLastname.ShowArrow();
     _currentLabel = lbLastname;
 }