设计模式.观察者模式(Observer)

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1、设计模式(DesignPattern)张凯副教授计算机学院软件工程系问题(Problem)晕，老板回来了，我不知道股市特别火，同事在上班期间偷偷看股票行情如果老板出门回来，公司前台MM电话事先通知可是…..老板今天刚一回来，让前台MM去打印资料了同事背对着大门大喊了一声“耶！我的股票涨停啦！”程序模拟发生的事情问题(Problem)classSecretary//前台秘书类{//同事列表privateIListobservers=newList();privat

2、estringaction;//增加publicvoidAttach(StockObserverobserver){observers.Add(observer);}//减少publicvoidDetach(StockObserverobserver){observers.Remove(observer);}//通知publicvoidNotify(){foreach(StockObserveroinobservers)o.Update();}//前台状态publicstringSecretaryAction{get{r

3、eturnaction;}set{action=value;}}}问题(Problem)//看股票的同事classStockObserver{privatestringname;privateSecretarysub;publicStockObserver(stringname,Secretarysub){this.name=name;this.sub=sub;}publicvoidUpdate(){Console.WriteLine("{0}{1}关闭股票行情，继续工作！",sub.SecretaryAction,na

4、me);}}问题(Problem)staticvoidMain(string[]args){//前台秘书MMSecretaryMM=newSecretary();//看股票的同事StockObservertongshi1=newStockObserver("魏关姹",MM);StockObservertongshi2=newStockObserver("易管查",MM);//前台记下了两位同事MM.Attach(tongshi1);MM.Attach(tongshi2);//发现老板回来MM.SecretaryActio

5、n="老板回来了！";//通知两个同事MM.Notify();Console.Read();}如果有人聊QQ，有人看NBA都需要通知，如何修改？思考：违背了那些原则？问题(Problem)//抽象观察者abstractclassObserver{protectedstringname;protectedSecretarysub;publicObserver(stringname,Secretarysub){this.name=name;this.sub=sub;}publicabstractvoidUpdate();}问

6、题(Problem)//看股票的同事classStockObserver:Observer{publicStockObserver(stringname,Secretarysub):base(name,sub){}publicoverridevoidUpdate(){Console.WriteLine("{0}{1}关闭股票行情，继续工作！",sub.SecretaryAction,name);}}//看NBA的同事classNBAObserver:Observer{publicNBAObserver(stringnam

7、e,Secretarysub):base(name,sub){}publicoverridevoidUpdate(){Console.WriteLine("{0}{1}关闭NBA直播，继续工作！",sub.SecretaryAction,name);}}问题(Problem)classSecretary//前台秘书类{//同事列表privateIListobservers=newList();privatestringaction;//增加publicvoidAttach(Obse

8、rverobserver){observers.Add(observer);}//减少publicvoidDetach(Observerobserver){observers.Remove(observer);}//通知publicvoidNotify(){foreach(Observeroinobservers)o