组合模式

 

 

要点：组合模式提供一个结构，可同时包容组合对象与个别对象。

组合模式容许客户对个别对象以及组合对象一视同仁。

组合结构内的任意对象成为组件。组件可以是组合，也可以是叶节点。

 

 

 

下面是组合模式的例子：

class Program 
    { 
        static void Main(string[] args) 
        { 
            //定义早餐==================================================================== 
            MenuComponent menu = new Menu("早餐", "新鲜的早餐");

            MenuComponent menuItem1 = new MenuItem("牛奶", "牛奶description", false, 3.0); 
            MenuComponent menuItem2 = new MenuItem("油条", "油条description", false, 1.0); 
            MenuComponent menuItem3 = new MenuItem("馒头", "馒头description", true, 1.0); 
            MenuComponent menuItem4 = new MenuItem("豆浆", "DoujiangDescription", true, 1.5); 
           
            menu.Add(menuItem1); 
            menu.Add(menuItem2); 
            menu.Add(menuItem3); 
            menu.Add(menuItem4);

            //定义午餐==================================================================== 
            MenuComponent lunch = new Menu("午餐", "包括下午茶"); 
            
            MenuComponent lunch1=new  MenuItem("香菇豆腐饭", "香菇豆腐", false, 10.5); 
            MenuComponent lunch2 = new MenuItem("蛋炒饭", "哈哈", false, 8.5); 
            MenuComponent lunch3 = new MenuItem("鱼香肉丝", "你猜", true, 15.5); 
            MenuComponent tea = new Menu("下午茶", "新鲜的下午茶");

            MenuComponent tea1 = new MenuItem("香蕉片", "香蕉片", true, 10); 
            MenuComponent tea2 = new MenuItem("咖啡", "大杯的哦", true, 10); 
            
            tea.Add(tea1); 
            tea.Add(tea2);

            lunch.Add(lunch1); 
            lunch.Add(lunch2); 
            lunch.Add(lunch3); 
            lunch.Add(tea);

            //定义三餐==================================================================== 
            MenuComponent food = new Menu("三餐", "三餐列表"); 
            food.Add(menu); 
            food.Add(lunch); 
            food.Print(); 
            Console.ReadKey(); 
        }

    }


    /// <summary> 
    /// 菜单组件 
    /// </summary> 
    public abstract class MenuComponent 
    { 
        public abstract void Add(MenuComponent menucomponent);

        public abstract  void Remove(MenuComponent menucomponent);

        public abstract MenuComponent GetChild(int i);

        public abstract string GetDescription();

        public abstract string GetName();

        public abstract double GetPrice();

        public abstract bool IsVegetarian(); 
  
        public abstract void Print(); 
    }

    public class MenuItem:MenuComponent 
    { 
        private string name; 
        private string description; 
        private bool vegetarin; 
        private double price;

        public MenuItem(string name, string description, bool vegetarin, double price) 
        { 
            this.name = name; 
            this.description = description; 
            this.vegetarin = vegetarin; 
            this.price = price; 
        }

        public override  string GetName() 
        { 
            return name; 
        }

        public override double GetPrice() 
        { 
            return price; 
        }

        public override bool IsVegetarian() 
        { 
            return vegetarin; 
        }

        public override string GetDescription() 
        { 
            return description; 
        }

        public override void Print() 
        { 
            Console.Write(""+GetName()+","); 
            if (IsVegetarian()) 
            { 
                Console.Write("（素） ,"); 
            } 
            Console.Write(GetPrice()+"￥,"); 
            Console.WriteLine(GetDescription()+"。"); 
        }

        public override MenuComponent GetChild(int i) 
        { 
            throw new NotImplementedException(); 
        }

        public override void Add(MenuComponent menucomponent) 
        { 
            throw new NotImplementedException(); 
        }

        public override void Remove(MenuComponent menucomponent) 
        { 
            throw new NotImplementedException(); 
        } 
    }

    public class Menu : MenuComponent 
    { 
        ArrayList menuComponents = new ArrayList(); 
        private string name; 
        private string description;

        public Menu(string name, string description) 
        { 
            this.name = name; 
            this.description = description; 
        }

        public override void Add(MenuComponent menucomponent) 
        { 
            menuComponents.Add(menucomponent); 
            return; 
        }

        public override void Remove(MenuComponent menucomponent) 
        { 
            menuComponents.Remove(menucomponent); 
        }


        public override string GetName() 
        { 
            return name; 
        }

        public override string GetDescription() 
        { 
            return description; 
        }

        public override void Print() 
        { 
            
            Console.Write("--"+GetName()); 
            Console.WriteLine("," + GetDescription());

            IEnumerator enumerator = menuComponents.GetEnumerator(); 
            while (enumerator.MoveNext()) 
            { 
                MenuComponent menuComponent = (MenuComponent)enumerator.Current; 
                menuComponent.Print(); 
            } 
        } 
        public override MenuComponent GetChild(int i) 
        { 
            throw new NotImplementedException(); 
        } 
        public override double GetPrice() 
        { 
            throw new NotImplementedException(); 
        }

        public override bool IsVegetarian() 
        { 
            throw new NotImplementedException(); 
        } 
    }