public void ListViewItem_PreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
ICollection <Element> selectedElems = new List <Element>();
ListViewItem item = sender as ListViewItem;
string elementIdAsString = (item.Content as MyListViewItem).Id;
TaskDialog.Show("title", $"{(item.Content as MyListViewItem).CategoryName} {elementIdAsString}");
Lab5Button.MakeSelection(_uidoc, elementIdAsString);
}
public new void MouseClick(object sender, RoutedEventArgs e)
{
Lab5Button.PopulateList();
}