代理模式
需求：
小明讓小李替他追小麗（送洋娃娃，送花，送巧克力）
沒有代理的代碼：
# -*- encoding: utf-8 -*-#追求者類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} 送你鮮花" end def give_chocolate puts "#{mm.name} 送你巧克力" endend#被追求者類class Girl attr_accessor :name def initialize(name) @name = name endendxiao_hong = Girl.new('小紅')xiao_ming = Pursuit.new(xiao_hong)xiao_ming.give_dollsxiao_ming.give_flowersxiao_ming.give_chocolate只有代理的代碼：
# -*- encoding: utf-8 -*-#代理類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} 送你鮮花" end def give_chocolate puts "#{mm.name} 送你巧克力" endend#被追求者類class Girl attr_accessor :name def initialize(name) @name = name endendxiao_hong = Girl.new('小紅')xiao_ming = Proxy.new(xiao_hong)xiao_ming.give_dollsxiao_ming.give_flowersxiao_ming.give_chocolate只是把追求者類換成了代理類。
實際的代理模式代碼：
# -*- encoding: utf-8 -*-#公共接口modulemodule GiveGift def give_dolls end def give_flowers end def give_chocolate endend#追求者類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}送你鮮花" end def give_chocolate puts "#{mm.name} 替#{name}送你巧克力" endend#代理類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#被追求者類class Girl attr_accessor :name def initialize(name) @name = name endendxiao_hong = Girl.new('小紅')xiao_ming = Proxy.new(xiao_hong)xiao_ming.gg.name = '小明'xiao_ming.give_dollsxiao_ming.give_flowersxiao_ming.give_chocolate
裝飾模式
需求：
給人搭配不同的服飾
代碼版本一
# -*- 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 '垮褲' end def wear_sneakers puts '破球鞋' end def wear_suit puts '西裝' end def wear_tie puts '領帶' end def wear_leather_shoes puts '皮鞋' end def show puts "*****裝扮的#{name}/n/n" endendxc=Person.new('小菜')puts "******第一種裝扮"xc.wear_t_shirtsxc.wear_big_trouserxc.wear_sneakersxc.showputs "******第二種裝扮"xc.wear_suitxc.wear_tiexc.wear_leather_shoesxc.show這樣寫的話，功能是實現了，問題是如果增加“超人”的裝扮，就要修改Person類，違反了開放-封閉原則。
代碼版本二
# -*- encoding: utf-8 -*-class Person attr_accessor :name def initialize(name) @name = name enddef show puts "*****裝扮的#{name}/n/n" endendclass Finery def show endendclass TShirts < Finery def show puts '大T恤' endendclass BigTrouser < Finery def show puts '垮褲' endendclass Sneakers < Finery def show puts '破球鞋' endendclass Suit < Finery def show puts '西裝' endendclass Tie < Finery def show puts '領帶' endendclass LeatherShoes < Finery def show puts '皮鞋' endendxc=Person.new('小菜')ts = TShirts.newbt = BigTrouser.newsk = Sneakers.newputs "******第一種裝扮"ts.showbt.showsk.showxc.showsuit = Suit.newtie = Tie.newls = LeatherShoes.newputs "******第二種裝扮"suit.showtie.showls.showxc.show這樣改了之后，如果增加超人裝扮，確實不需要去修改Person類。存在的問題是，各種衣服是獨立的，并且暴露在外邊的，就是一件一件穿的，沒有順序，沒有控制。
代碼版本三
# -*- encoding: utf-8 -*-class Person attr_accessor :name def initialize(name=nil) @name = name end def show puts "*****裝扮的#{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 '垮褲' endendclass Sneakers < Finery def show super puts '破球鞋' endendclass Suit < Finery def show super puts '西裝' endendclass Tie < Finery def show super puts '領帶' endendclass LeatherShoes < Finery def show super puts '皮鞋' endendxc=Person.new('小菜')ts = TShirts.newbt = BigTrouser.newsk = Sneakers.newputs "******第一種裝扮"ts.decorate xcbt.decorate tssk.decorate btsk.showsuit = Suit.newtie = Tie.newls = LeatherShoes.newputs "******第二種裝扮"suit.decorate xctie.decorate suitls.decorate btls.show新聞熱點
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