private void btn_RemoveFirst_Click(object sender, RoutedEventArgs e) { if (list.Size() > 0) { list.RemoveFirst(); l_ListaSize.Content = string.Concat("List size: ", list.Size()); lV_Lista.Items.Clear(); if (list.Size() > 0) { foreach (string s in list) { lV_Lista.Items.Add(s); } } } }