CSharp设计模式读书笔记（2）：工厂方法模式(学习难度：★★☆☆☆，使用频率：★★★★★)

工厂方法模式(Factory Method Pattern)：定义一个用于创建对象的接口，让子类决定将哪一个类实例化。工厂方法模式让一个类的实例化延迟到其子类。工厂方法模式又简称为工厂模式(Factory Pattern)，又可称作虚拟构造器模式(Virtual Constructor Pattern)或多态工厂模式(Polymorphic Factory Pattern)。

模式角色与结构：

工厂方法模式是类的创建模式，其用意是定义一个创建产品对象的接口，将实际创建工作推迟到子类中。

示例代码：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace CSharp.DesignPattern.FactoryMethodPattern
{
    class Program
    {
        static void Main(string[] args)
        {
            ICreator footballCreator = new FootballCreator(); // build factory
            ICreator baseketballCreator = new BaseketballCreator(); // build factory

            IAthlete footballAthlete = footballCreator.Create(); // build product
            IAthlete basketballAthlete = baseketballCreator.Create(); // build product

            footballAthlete.Run();
            footballAthlete.Jump();

            basketballAthlete.Run();
            basketballAthlete.Jump();

            Console.ReadLine();
        }
    }

    // Product
    interface IAthlete 
    {
        void Run();
        void Jump();
    }

    class FootballAthlete : IAthlete
    {
        public void Run()
        {
            Console.WriteLine("FootballAthlete Run...");
        }

        public void Jump()
        {
            Console.WriteLine("FootballAthlete Jump...");
        }
    }

    class BaseketballAthlete : IAthlete
    {
        public void Run()
        {
            Console.WriteLine("BaseketballAthlete Run...");
        }

        public void Jump()
        {
            Console.WriteLine("BaseketballAthlete Jump...");
        }
    }

    // Factory
    interface ICreator 
    {
        IAthlete Create();
    }

    // Concrete Factory
    class BaseketballCreator : ICreator 
    {
        public IAthlete Create()
        {
            return new BaseketballAthlete();
        }
    }

    // Concrete Factory
    class FootballCreator : ICreator 
    {
        public IAthlete Create()
        {
            return new FootballAthlete();
        }
    }
}