谈谈桥接模式

先打个比方，设计模式犹如古代武术家的内功，内功的修为决定着写出的程序是否容易扩展，是否便于维护，体现了高内聚，松耦合的设计方法。桥接模式将对象的抽象与对象的实现分离。现在分享一下我的小作。

//=================design by mahong ==================
//================design date 2009-11-28===============
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace BridgePattern
{
    //抽象类大杯、中杯、小杯，即对象的抽象
    public abstract class Drink
    {
        //定义对象的实现接口
        SetMilkOrNot setOrNot;
        public void SetTheType()
        {
            setOrNot = SetMilkOrNotSingleton.GetTheMilkIsSetOrNot();
        }
        public SetMilkOrNot GetTheType()
        {
            return setOrNot;
        }
        //定义方法，此方法调用4次，表明是大杯，2次表明是中杯
        public abstract void PourDrink();
    }
    //抽象类是否加奶，即对象的实现
    public abstract class SetMilkOrNot
    {
        public abstract void SetOrNot();
    }
    //中杯
    public class MediumCup : Drink
    {
        public MediumCup()
        {
            SetTheType();
        }
        public override void PourDrink()
        {
            SetMilkOrNot son = GetTheType();
            for (int i = 0; i < 2; i++)
            {
                son.SetOrNot();
            }
        }
    }
    //大杯
    public class BigCup : Drink
    {
        public BigCup()
        {
            SetTheType();
        }
        public override void PourDrink()
        {
            SetMilkOrNot son = GetTheType();
            for (int i = 0; i < 4; i++)
            {
                son.SetOrNot();
            }
        }
    }
    //加奶
    public class AddMilk : SetMilkOrNot
    {
        public AddMilk() { }
        public override void SetOrNot()
        {
            Console.WriteLine("加奶");            
        }
    }
    //不加奶
    public class UnAddMilk : SetMilkOrNot
    {
        public UnAddMilk() { }
        public override void SetOrNot()
        {
            Console.WriteLine("不加奶");
        }
    }
    //单例，静态创建加不加奶的对象
    public class SetMilkOrNotSingleton
    {
        public static SetMilkOrNot isSetOrNot;
        public SetMilkOrNotSingleton(SetMilkOrNot son)
        {
            isSetOrNot = son;
        }
        public static SetMilkOrNot GetTheMilkIsSetOrNot()
        {
            return isSetOrNot;
        }
    }

    class Program
    {
        static void Main(string[] args)
        {
            //加奶
            SetMilkOrNotSingleton add = new SetMilkOrNotSingleton(new AddMilk());
            
            //大杯加奶
            BigCup big = new BigCup();
            big.PourDrink();
            Console.WriteLine("=====================");
            //中杯加奶
            MediumCup mediun = new MediumCup();
            mediun.PourDrink();

            Console.Read();

            //不加奶
            SetMilkOrNotSingleton unAdd = new SetMilkOrNotSingleton(new UnAddMilk());
            //大杯加奶
            BigCup big1 = new BigCup();
            big1.PourDrink();
            Console.WriteLine("=====================");
            //中杯加奶
            MediumCup mediun1 = new MediumCup();
            mediun1.PourDrink();

            Console.ReadLine();
            Console.Read();
        }
    }
}

以上代码量并不多，但反应了桥接模式的大概设计思想理念。