设计模式--工厂模式大集合

public enum CarEnum
    {
        BMWCar,
        MercedesCar,
        HondaCar,
    }

    public abstract class Car
    {
        public abstract Car CreateCar();
    }


    public class BMW : Car
    {
        public override Car CreateCar()
        {
            Console.WriteLine("哦天哪，宝马车造好了");
            return new BMW();
        }
    }

    public class Mercedes : Car
    {
        public override Car CreateCar()
        {
            Console.WriteLine("太好了，奔驰车造好了");
            return new Mercedes();
        }
    }

    public class Honda : Car
    {
        public override Car CreateCar()
        {
            Console.WriteLine("棒极了,本田车造好了");
            return new Honda();
        }
    }

    /// <summary>
    /// 简单工厂模式，通过接收不同的参数，来创建不同的实例
    /// 缺点：不修改原有代码吗，无法扩展（如果增加新的产品，需要加入switch分支）
    /// 不符【开放封闭原则】
    /// </summary>
    public static class SimpleFactory
    {
        public static Car CreateCar(CarEnum carName)
        {
            Car car = null;
            switch (carName)
            {
                case CarEnum.BMWCar:
                     car = new BMW();
                    break;

                case CarEnum.MercedesCar:
                    car = new Mercedes();
                    break;

                case CarEnum.HondaCar:
                    car = new Honda();
                    break;
                default:
                    break;
            }
            return car;
        }
    }