private void btn_AddLast_Click(object sender, RoutedEventArgs e) { if (string.IsNullOrEmpty(tB_Elemento.Text)) { MessageBox.Show("Error, campo de añadir vacio."); return; } string s = tB_Elemento.Text; list.AddLast(s); l_ListaSize.Content = string.Concat("List size: ", list.Size()); lV_Lista.Items.Clear(); foreach (string t in list) { lV_Lista.Items.Add(t); } }