private void button1_Click(object sender, RoutedEventArgs e) { ICar car = CarCreate.Create((Cars)comboBox3.SelectedValue); if (car == null) { this.Close(); } car.Body(); car.Brush((ConsoleColor)comboBox1.SelectedValue); car.Doors(Convert.ToInt32(comboBox2.SelectedValue)); car.Tyres(); MessageBox.Show(car.ToString()); }