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" endend#被追求者类class Girl attr_accessor :name def initialize(name) @name = name endendxiao_hong = Girl.new('小红')xiao_ming = Pursuit.new(xiao_hong)xiao_ming.give_dollsxiao_ming.give_flowersxiao_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" endend#被追求者类class Girl attr_accessor :name def initialize(name) @name = name endendxiao_hong = Girl.new('小红')xiao_ming = Proxy.new(xiao_hong)xiao_ming.give_dollsxiao_ming.give_flowersxiao_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modulemodule GiveGift def give_dolls end def give_flowers end def give_chocolate endend#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" endend#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 endend#被追求者类class Girl attr_accessor :name def initialize(name) @name = name endendxiao_hong = Girl.new('小红')xiao_ming = Proxy.new(xiao_hong)xiao_ming.gg.name = '小明'xiao_ming.give_dollsxiao_ming.give_flowersxiao_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}\n\n" endendxc=Person.new('小菜')puts "******第一种装扮"xc.wear_t_shirtsxc.wear_big_trouserxc.wear_sneakersxc.showputs "******第二种装扮"xc.wear_suitxc.wear_tiexc.wear_leather_shoesxc.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}\n\n" endendclass Finery def show endendclass TShirts < Finery def show puts '大T恤' endendclass BigTrouser < Finery def show puts '垮裤' endendclass Sneakers < Finery def show puts '破球鞋' endendclass Suit < Finery def show puts '西装' endendclass Tie < Finery def show puts '领带' endendclass LeatherShoes < Finery def show puts '皮鞋' endendxc=Person.new('小菜')ts = TShirts.newbt = BigTrouser.newsk = Sneakers.newputs "******第一种装扮"ts.showbt.showsk.showxc.showsuit = Suit.newtie = Tie.newls = LeatherShoes.newputs "******第二种装扮"suit.showtie.showls.showxc.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}\n\n" endendclass Finery < Person attr_accessor :componet def decorate(componet) @componet = componet end def show componet.show if componet endendclass TShirts < Finery def show super puts '大T恤' endendclass BigTrouser < Finery def show super puts '垮裤' endendclass Sneakers < Finery def show super puts '破球鞋' endendclass Suit < Finery def show super puts '西装' endendclass Tie < Finery def show super puts '领带' endendclass LeatherShoes < Finery def show super puts '皮鞋' endendxc=Person.new('小菜')ts = TShirts.newbt = BigTrouser.newsk = Sneakers.newputs "******第一种装扮"ts.decorate xcbt.decorate tssk.decorate btsk.showsuit = Suit.newtie = Tie.newls = LeatherShoes.newputs "******第二种装扮"suit.decorate xctie.decorate suitls.decorate btls.show