设计模式-------建造者

建造者模式用于 通过不同的步骤创建不同的对象

各步骤之间相对独立的情况

以 快餐店 烹制 快餐 为例

快餐 可以分为两部分 饮品(drink)和食品(food)

通过两步相对独立的操作 烹制饮品 和 烹制 食品

即可完成不同内容的 快餐

假定有两个厨师(cooker) 一位 cooker_zhou 另一位 cooker_li

由前台的接待(Director)根据顾客要求决定哪一位厨师来完成快餐

示例代码:

using System;
using System.Collections.Generic;

namespace DesignPatterns.CreatePatterns.Builder
{
    public class Meal
    {
        private List<string> parts = null;
        public Meal()
        {
            parts = new List<string>();
        }
        public void Add(string part)
        {
            parts.Add(part);
        }

        public void  ShowMeal()
        {
            Console.WriteLine("Meal contents as follow:");
            foreach (string part in parts)
            {
                Console.WriteLine(part);
            }
        }
    }

    public abstract class Cooker
    {
        public abstract void CookDrink();
        public abstract void CookFood();
        public abstract Meal GetMeal();
    }

    class CookerLi : Cooker
    {
        private Meal meal = new Meal();
        public override void CookDrink()
        {
            meal.Add("orange juice");
        }
        public override void CookFood()
        {
            meal.Add("Fried Chicken");
        }
        public override Meal GetMeal()
        {
            return meal;
        }
    }

    class CookerZhou : Cooker
    {
        private Meal meal = new Meal();
        public override void CookDrink()
        {
            meal.Add("QingDao Beer");
        }
        public override void CookFood()
        {
            meal.Add("Konpao Beaf");
        }
        public override Meal GetMeal()
        {
            return meal;
        }
    }

    class Director
    {
        public void AskMealForCooker(Cooker cooker)
        {
            cooker.CookDrink();
            cooker.CookFood();
        }
    }
}

调用示例:

            CookerLi cooker_li = new CookerLi();
            CookerZhou cooker_zhou = new CookerZhou();
            Director director = new Director();
            director.AskMealForCooker(cooker_li);
            Meal meal_li = cooker_li.GetMeal();
            meal_li.ShowMeal();

            director.AskMealForCooker(cooker_zhou);
            Meal meal_zhou = cooker_zhou.GetMeal();
            meal_zhou.ShowMeal();