工厂方法模式

故事：

　　有个定制鞋子的工厂（还是那个工厂）（因为使用了设计模式应对了各种变化）效益比较好，决定把生产部门分成两个部门（休闲鞋部门/运动鞋部门）。每个部门生产相应的鞋子类型。

建模：

　　工厂运动鞋生产部门/工厂休闲鞋生产部门。

　　工厂前台接待处。

　　鞋子。

　　你还是这个工厂的客户。

类图：

实现：

HelpDesk

namespace FactoryMethod
{
    public class HelpDesk
    {
        ArrayList al = new ArrayList();
        public HelpDesk()
        {
            SportsShoesDepartment ss = new SportsShoesDepartment();
            al.Add(ss);
            LeisureShoesDepartment ls = new LeisureShoesDepartment();
            al.Add(ls);
        }
        
        public Shoes produceShoes(string shoesType)
        {
            Shoes shoes;
            Console.WriteLine("<工厂公告>客户需要的鞋子类型是:{0}\n", shoesType);
            foreach(ShoesFactoryDepartment sfd in al)
            {
                shoes = sfd.produceShoes(shoesType);
                if (shoes != null)
                {
                    return shoes;
                }
            }
            return null;
        }
    }
}

ShoesFactoryDepartment

namespace FactoryMethod
{
    public abstract class ShoesFactoryDepartment
    {
        public abstract Shoes produceShoes(string shoesType);
    }
}

SportsShoesDepartment

namespace FactoryMethod
{
    public class SportsShoesDepartment: ShoesFactoryDepartment
    {
        public override Shoes produceShoes(string shoesType)
        {
            if (shoesType == "Sport")
            {
                return new SportShoes();
            }
            else
            {
                return null;
            }
        }
    }
}

LeisureShoesDepartment

namespace FactoryMethod
{
    public class LeisureShoesDepartment: ShoesFactoryDepartment
    {
        public override Shoes produceShoes(string shoesType)
        {
            if (shoesType == "Leisure")
            {
                return new LeisureShoes();
            }
            else
            {
                return null;
            }
        }
    }
}

Program

namespace FactoryMethod
{
    class Program
    {
        static void Main(string[] args)
        {
            HelpDesk helpDesk = new HelpDesk();

            Console.WriteLine("请输入你想要的鞋子：Sport/Leisure");
            string shoesType = Console.ReadLine();

            Console.WriteLine("\n------进厂定制---------\n");
            helpDesk.produceShoes(shoesType);
            Console.WriteLine("\n-------鞋子出厂--------\n");
            
        }
    }
}

效果：