代理模式

需求：

小明让小李替他追小丽（送洋娃娃，送花，送巧克力）

没有代理的代码：

# -*- encoding: utf-8 -*- #追求者类 class Pursuit attr_accessor :mm def initialize(mm) @mm = mm end def give_dolls puts "#{mm.name} 送你洋娃娃" end def give_flowers puts "#{mm.name} 送你鲜花" end def give_chocolate puts "#{mm.name} 送你巧克力" end end #被追求者类 class Girl attr_accessor :name def initialize(name) @name = name end end xiao_hong = Girl.new('小红') xiao_ming = Pursuit.new(xiao_hong) xiao_ming.give_dolls xiao_ming.give_flowers xiao_ming.give_chocolate

只有代理的代码：

# -*- encoding: utf-8 -*- #代理类 class Proxy attr_accessor :mm def initialize(mm) @mm = mm end def give_dolls puts "#{mm.name} 送你洋娃娃" end def give_flowers puts "#{mm.name} 送你鲜花" end def give_chocolate puts "#{mm.name} 送你巧克力" end end #被追求者类 class Girl attr_accessor :name def initialize(name) @name = name end end xiao_hong = Girl.new('小红') xiao_ming = Proxy.new(xiao_hong) xiao_ming.give_dolls xiao_ming.give_flowers xiao_ming.give_chocolate

只是把追求者类换成了代理类。

实际的代理模式代码：

# -*- encoding: utf-8 -*- #公共接口module module GiveGift def give_dolls end def give_flowers end def give_chocolate end end #追求者类 class Pursuit include GiveGift attr_accessor :mm, :name def initialize(mm) @mm = mm end def give_dolls puts "#{mm.name} 替#{name}送你洋娃娃" end def give_flowers puts "#{mm.name} 替#{name}送你鲜花" end def give_chocolate puts "#{mm.name} 替#{name}送你巧克力" end end #代理类 class Proxy include GiveGift attr_accessor :gg def initialize(mm) @gg = Pursuit.new(mm) end def give_dolls gg.give_dolls end def give_flowers gg.give_flowers end def give_chocolate gg.give_chocolate end end #被追求者类 class Girl attr_accessor :name def initialize(name) @name = name end end xiao_hong = Girl.new('小红') xiao_ming = Proxy.new(xiao_hong) xiao_ming.gg.name = '小明' xiao_ming.give_dolls xiao_ming.give_flowers xiao_ming.give_chocolate

装饰模式

需求：

给人搭配不同的服饰

代码版本一

# -*- encoding: utf-8 -*- class Person attr_accessor :name def initialize(name) @name = name end def wear_t_shirts puts '大T恤' end def wear_big_trouser puts '垮裤' end def wear_sneakers puts '破球鞋' end def wear_suit puts '西装' end def wear_tie puts '领带' end def wear_leather_shoes puts '皮鞋' end def show puts "*****装扮的#{name}nn" end end xc=Person.new('小菜') puts "******第一种装扮" xc.wear_t_shirts xc.wear_big_trouser xc.wear_sneakers xc.show puts "******第二种装扮" xc.wear_suit xc.wear_tie xc.wear_leather_shoes xc.show

这样写的话，功能是实现了，问题是如果增加“超人”的装扮，就要修改Person类，违反了开放-封闭原则。

代码版本二

# -*- encoding: utf-8 -*- class Person attr_accessor :name def initialize(name) @name = name enddef show puts "*****装扮的#{name}nn" end end class Finery def show end end class TShirts < Finery def show puts '大T恤' end end class BigTrouser < Finery def show puts '垮裤' end end class Sneakers < Finery def show puts '破球鞋' end end class Suit < Finery def show puts '西装' end end class Tie < Finery def show puts '领带' end end class LeatherShoes < Finery def show puts '皮鞋' end end xc=Person.new('小菜') ts = TShirts.new bt = BigTrouser.new sk = Sneakers.new puts "******第一种装扮" ts.show bt.show sk.show xc.show suit = Suit.new tie = Tie.new ls = LeatherShoes.new puts "******第二种装扮" suit.show tie.show ls.show xc.show

这样改了之后，如果增加超人装扮，确实不需要去修改Person类。存在的问题是，各种衣服是独立的，并且暴露在外边的，就是一件一件穿的，没有顺序，没有控制。

代码版本三

# -*- encoding: utf-8 -*- class Person attr_accessor :name def initialize(name=nil) @name = name end def show puts "*****装扮的#{name}nn" end end class Finery < Person attr_accessor :componet def decorate(componet) @componet = componet end def show componet.show if componet end end class TShirts < Finery def show super puts '大T恤' end end class BigTrouser < Finery def show super puts '垮裤' end end class Sneakers < Finery def show super puts '破球鞋' end end class Suit < Finery def show super puts '西装' end end class Tie < Finery def show super puts '领带' end end class LeatherShoes < Finery def show super puts '皮鞋' end end xc=Person.new('小菜') ts = TShirts.new bt = BigTrouser.new sk = Sneakers.new puts "******第一种装扮" ts.decorate xc bt.decorate ts sk.decorate bt sk.show suit = Suit.new tie = Tie.new ls = LeatherShoes.new puts "******第二种装扮" suit.decorate xc tie.decorate suit ls.decorate bt ls.show