Composite Pattern (10)
组合模式：
将对象组织成树形结构的形式来表现部分和整体的继承关系。组合模式让客户将独立的叶节点对象和枝节点对象进行统一处理。
示例代码：
using System;
using
System.Text;
using
System.IO;
using
System.Collections.Generic;
namespace Hello
{
//self-define Exception
public class UnsopportedOperationException : ApplicationException
{
}
//Node abstract class
public abstract class MenuComponent
{
public virtual void Add(MenuComponent
menuComponent)
{
throw new UnsopportedOperationException();
}
public virtual void Remove(MenuComponent
menuComponent)
{
throw new UnsopportedOperationException();
}
public virtual MenuComponent GetChild(int
i)
{
throw new UnsopportedOperationException();
}
public virtual string GetName()
{
throw new UnsopportedOperationException();
}
public virtual string GetDescription()
{
throw new UnsopportedOperationException();
}
public virtual double GetPrice()
{
throw new UnsopportedOperationException();
}
public virtual bool IsVegetarian()
{
throw new UnsopportedOperationException();
}
public virtual void Print()
{
throw new UnsopportedOperationException();
}
}
//Leaf Node Clas
public class MenuItem : MenuComponent
{
string name;
string description;
bool vegetarian;
double price;
public MenuItem(string
name, string description, bool vegetarian, double
price)
{
this.name = name;
this.description = description;
this.vegetarian = vegetarian;
this.price = price;
}
public override string GetName()
{
return name;
}
public override string GetDescription()
{
return description;
}
public override double GetPrice()
{
return price;
}
public override bool IsVegetarian()
{
return vegetarian;
}
public override void Print()
{
Console.Write(GetName());
if (IsVegetarian())
{
Console.WriteLine("(V)");
}
Console.Write("--"
+ GetPrice());
Console.WriteLine("--"
+ GetDescription());
}
}
//Branch Node Class
public class Menu : MenuComponent
{
List<MenuComponent>
menuComponents = new List<MenuComponent>();
string name;
string description;
public Menu(string
name, string description)
{
this.name = name;
this.description = description;
}
public override void Add(MenuComponent
menuComponent)
{
menuComponents.Add(menuComponent);
}
public override void Remove(MenuComponent
menuComponent)
{
menuComponents.Remove(menuComponent);
}
public override MenuComponent GetChild(int
i)
{
return menuComponents[i];
}
public override string GetName()
{
return name;
}
public override string GetDescription()
{
return description;
}
public override void Print()
{
Console.Write("\n"
+ GetName());
Console.WriteLine(",
" + GetDescription());
Console.WriteLine("-----------------------");
}
}
class Program
{
static void Main(string[] args)
{
MenuComponent pancakeHouseMenu = new Menu("PANCAKE HOUSE MENU", "Breakfast");
MenuComponent dinerMenu = new
Menu("DINER
MENU", "Lunch");
MenuComponent cafeMenu = new
Menu("CAFE
MENU", "Dinner");
MenuComponent dessertMenu = new Menu("DESSERT MENU", "Dessert
of course!");
MenuComponent allMenus = new
Menu("ALL
MENUS", "All menus Combined");
allMenus.Add(pancakeHouseMenu);
allMenus.Add(dinerMenu);
allMenus.Add(cafeMenu);
dinerMenu.Add(new MenuItem("Pasta","xxx
xxx xx x xx x xxx",true,3.89));
dinerMenu.Add(dessertMenu);
dessertMenu.Add(new MenuItem("Apple Pie", "Apple
Pie with xx xxx x", true, 1.59));
}
}
}
