C#适配器模式

前言

我昨天做了个梦，我梦见我在一条路走，走的时候经过一个房间，里面关着一条边牧和鸡和猪，后来我醒了，我知道那只边牧就是小叶子(哈仔十一的边牧)，小叶子具备牧羊和牧鸡的技能，因此，假如我想把一只边牧或者一只狗变成小叶子那样，那么首先就得让其赋予牧鸡的本事，而十一(哈仔十一的哈士奇)则具备卖萌的技能

适配器模式

我们先定义一些代码

    internal interface IDog    {        public void Eat();        public void Bark();    }    /// <summary>    /// 哈士奇    /// </summary>    internal interface IHuskyDog:IDog    {        /// <summary>        /// 破坏、拆家        /// </summary>        public void Demolition();    }    /// <summary>    /// 牧羊犬    /// </summary>    internal interface IShepherdDog:IDog    {        /// <summary>        /// 牧羊        /// </summary>        public void Shepherd();    }    /// <summary>    /// 小叶子、小椰汁    /// </summary>    internal class XiaoYezi : IShepherdDog    {        public void Bark()        {            Console.WriteLine($"I Am {nameof(XiaoYezi)} 汪 汪 汪 !!!!!");        }        public void Eat()        {            Console.WriteLine($"I Am {nameof(XiaoYezi)} 好吃 !!!!!");        }        /// <summary>        /// 牧羊        /// </summary>        public void Shepherd()        {            Console.WriteLine($"I Am {nameof(XiaoYezi)}， 我在牧羊 !!!!!");        }    }    /// <summary>    /// 十一    /// </summary>    internal class ShiYi : IHuskyDog    {        public void Bark()        {            Console.WriteLine($"I Am {nameof(ShiYi)} 汪 汪 汪 !!!!!");        }        public void Demolition()        {            Console.WriteLine($"I Am {nameof(ShiYi)} ,拆家啦 !!!!!");        }        public void Eat()        {            Console.WriteLine($"I Am {nameof(ShiYi)} 好吃得停不下来 !!!!!");        }    }

那么，用代码怎么写呢？或许你会定义一个变叶子的接口，有个方法叫HerdingChicken ,让其实现牧鸡的技能就行，但是实际上这里有两个主要问题：

• 叶子本身是一个狗，如果其他人实现了这个接口，他能变叶子？是不是前提他是狗
• 假如叶子不单单只是牧鸡，她会牧鹅、猪、牧自己？还得多接口，或者在变叶子的接口加方法给其实现

这时候适配器模式就是可以适应这种情况：

 internal class XiaoYeziAdapter : IShepherdDog    {        public IDog Dog { get; set; }        public XiaoYeziAdapter(IDog dog)        {            Dog = dog;        }        public void Bark()        {            Dog.Bark();        }        public void Eat()        {            Dog.Eat();        }        public void Shepherd()        {            if (Dog is IShepherdDog shepherdDog)            {                shepherdDog.Shepherd();            }        }        /// <summary>        /// 牧鸡        /// </summary>        public void HerdingChicken()        {            Console.WriteLine($"{Dog.GetType().Name} is Herding Chicken");        }    }

代码如下：

var xiaoYezi = new XiaoYezi();var xiaoYeziAdapter = new XiaoYeziAdapter(xiaoYezi);xiaoYeziAdapter.Bark();xiaoYeziAdapter.Eat();xiaoYeziAdapter.HerdingChicken();Console.WriteLine("---------------- \n");var shiYi = new ShiYi();xiaoYeziAdapter = new XiaoYeziAdapter(shiYi);xiaoYeziAdapter.Bark();xiaoYeziAdapter.Eat();xiaoYeziAdapter.HerdingChicken();

输出：

I Am XiaoYezi 汪 汪 汪 !!!!!I Am XiaoYezi 好吃 !!!!!XiaoYezi 在牧鸡----------------I Am ShiYi 汪 汪 汪 !!!!!I Am ShiYi 好吃得停不下来 !!!!!ShiYi 在牧鸡

可以看到，十一用了小叶子适配器，也具备了牧鸡的功能

那么反过来，叶子变十一呢？那就定义一个十一适配器呗

 internal class ShiYiAdapter : IHuskyDog    {        public IDog Dog { get; set; }        public ShiYiAdapter(IDog dog)        {            Dog=dog;        }        /// <summary>        /// 吠        /// </summary>        /// <exception cref="NotImplementedException"></exception>        public void Bark()        {            Dog.Bark();        }        /// <summary>        /// 拆家        /// </summary>        /// <exception cref="NotImplementedException"></exception>        public void Demolition()        {            if (Dog is IHuskyDog huskyDog)            {                huskyDog.Demolition();            }        }        /// <summary>        /// 吃        /// </summary>        /// <exception cref="NotImplementedException"></exception>        public void Eat()        {            Dog.Eat();        }        /// <summary>        /// 卖萌        /// </summary>        public void ActingCute()        {            Console.WriteLine($"{Dog.GetType().Name} 卖萌啦！！");        }    }

代码如下：

var xiaoYezi = new XiaoYezi();var shiYiAdapter = new ShiYiAdapter(xiaoYezi);shiYiAdapter.Bark();shiYiAdapter.ActingCute();shiYiAdapter.Demolition();Console.WriteLine("---------------- \n");var shiYi = new ShiYi();shiYiAdapter = new ShiYiAdapter(shiYi);shiYiAdapter.Bark();shiYiAdapter.ActingCute();shiYiAdapter.Demolition();

输出：

I Am XiaoYezi 汪 汪 汪 !!!!!XiaoYezi 卖萌啦！！----------------I Am ShiYi 汪 汪 汪 !!!!!ShiYi 卖萌啦！！I Am ShiYi ,拆家啦 !!!!!

看，小叶子具备卖萌的技能了，而且由于拆家是哈士奇的技能，因此小叶子拆家没拆到，实际上，或者卖萌和牧鸡只是哈仔十一(大哈)家的特色，那么是不是可以定义一个大哈家的适配器

    /// <summary>    /// 哈仔十一家的狗适配器    /// </summary>    internal class DaHaFamilyDogAdapter    {        public IDog Dog { get; set; }        public DaHaFamilyDogAdapter(IDog dog)        {            Dog = dog;        }        /// <summary>        /// 牧鸡        /// </summary>        public void HerdingChicken()        {            Console.WriteLine($"{Dog.GetType().Name} 在牧鸡");        }        /// <summary>        /// 卖萌        /// </summary>        public void ActingCute()        {            Console.WriteLine($"{Dog.GetType().Name} 在卖萌");        }    }

那么

var xiaoYezi = new XiaoYezi();var daHaFamilyDogAdapter = new DaHaFamilyDogAdapter(xiaoYezi);daHaFamilyDogAdapter.Bark();daHaFamilyDogAdapter.Eat();daHaFamilyDogAdapter.HerdingChicken();daHaFamilyDogAdapter.ActingCute();Console.WriteLine("---------------- \n");var shiYi = new ShiYi();daHaFamilyDogAdapter = new DaHaFamilyDogAdapter(shiYi);daHaFamilyDogAdapter.Bark();daHaFamilyDogAdapter.Eat();daHaFamilyDogAdapter.HerdingChicken();daHaFamilyDogAdapter.ActingCute();

输出：

I Am XiaoYezi 汪 汪 汪 !!!!!I Am XiaoYezi 好吃 !!!!!XiaoYezi 在牧鸡XiaoYezi 在卖萌----------------I Am ShiYi 汪 汪 汪 !!!!!I Am ShiYi 好吃得停不下来 !!!!!ShiYi 在牧鸡ShiYi 在卖萌