设计模式系列：工厂方法模式（Factory Method Pattern）

1.介绍

工厂方法模式是一种常用的类创建型设计模式,此模式的核心精神是封装类中变化的部分，

提取其中个性化善变的部分为独立类，通过依赖注入以达到解耦、复用和方便后期维护拓展的目的。

它的核心结构有四个角色，分别是抽象工厂；具体工厂；抽象产品；具体产品

2.示例

    public class Human : IRace
    {
        public void ShowKing()
        {
            Console.WriteLine("The king of Human is Sky");
        }
    }

    public class NE : IRace
    {
        public void ShowKing()
        {
            Console.WriteLine("The king of NE is Moon");
        }
    }

    public class Orc : IRace
    {
        public void ShowKing()
        {
            Console.WriteLine("The king of Orc is Grubby");
        }
    }

    public class Undead : IRace
    {
        public void ShowKing()
        {
            Console.WriteLine("The king of Undead is Gostop");
        }
    }

3.工厂方法接口

    public interface IFactoryMethod
    {
        IRace CreateInstance();
    }

    public class HumanFactory : IFactoryMethod
    {
        public IRace CreateInstance()
        {
            return new Human();
        }
    }

    public class NEFactory : IFactoryMethod
    {
        public IRace CreateInstance()
        {
            return new NE();
        }
    }

    public class OrcFactory : IFactoryMethod
    {
        public IRace CreateInstance()
        {
            return new Orc();
        }
    }

    public class UndeadFactory : IFactoryMethod
    {
        public IRace CreateInstance()
        {
            return new Undead();
        }
    }

    class Program
    {
        static void Main(string[] args)
        {

            Human human2 = new Human();
            human2.ShowKing();
            //IRace human1 = new Human();

            IFactoryMethod humanFactory = new HumanFactory();
            IRace human = humanFactory.CreateInstance();
            human.ShowKing();
            Console.Read();
        }
    }