设计模式学习笔记之十六observer观察者模式

1、设计模式 C+学习笔记之十六（Observer 观察者模式）16.1.解释概念：定义对象间的一种一对多的依赖关系，当一个对象的状态发生改变时，所有依赖于它的对象都得到通知并被自动更新。main()，IObservable，被观察者接口CHanFeiZiObservable，被观察者IObserver，观察者接口CLiSiObserver，观察者CZhouSiObserver 观察者说明：将观察者到被观察者身边，的每一个举动都会通知给观察者，如或。注意：最多允许一个对象既是观察者也是被观察者。就像数据库中的触发器一样，成为一个复杂的链就很难了。观察者类似于委托的处理方式。/IObservable

2、.h#pragma once #include IObserver.h #include using std:string;class IObservablepublic:IObservable(void)virtual IObservable(void)virtual void AddObserver(IObserver *pObserver) = 0; virtual void DeleteObserver(IObserver *pObserver) = 0; virtual void NotifyObservers(string context) = 0;/HanFeiziObserva

3、ble.h#pragma once#include iobservable.h #include IObserver.h #include using std:vector;class CHanFeiziObservable : public IObservablepublic:CHanFeiziObservable(void);CHanFeiziObservable(void);void AddObserver(IObserver *pObserver); void DeleteObserver(IObserver *pObserver); void NotifyObservers(stri

4、ng context);void HaveBreakfast(); void HaveFun();private:vector m_observerList;typedef vector:const_iterator ObserverList_C_iterator;/HanFeiziObservable.cpp#include StdAfx.h#include HanFeiziObservable.h #include using std:string; using std:cout; using std:endl;CHanFeiziObservable:CHanFeiziObservable

5、(void)CHanFeiziObservable:CHanFeiziObservable(void)void CHanFeiziObservable:AddObserver( IObserver *pObserver )m_observerList.push_back(pObserver);void CHanFeiziObservable:DeleteObserver( IObserver *pObserver )ObserverList_C_iterator it = m_observerList.begin(); for (; it != m_observerList.end(); it

6、+)string name = (*it)-GetName();if (pare(pObserver-GetName() = 0)/找到了删除。void CHanFeiziObservable:NotifyObservers( string context )ObserverList_C_iterator it = m_observerList.begin(); for (; it != m_observerList.end(); it +)(*it)-Update(context);void CHanFeiziObservable:HaveBreakfast()cout ：开始吃饭了. No

7、tifyObservers(在吃饭);void CHanFeiziObservable:HaveFun()cout ：开始了. NotifyObservers(在);/IObserver.h#pragma once #include using std:string; class IObserverpublic:IObserver(string _name)this-m_name = _name;virtual IObserver(void)virtual void Update(string context) = 0;virtual string GetName() = 0;/为c+单独增加

8、的函数，用于删除时查找观察者。 protected:string m_name;/LiSiObserver.h#pragma once#include iobserver.h#include using std:string; class CLiSiObserver :public IObserverpublic:CLiSiObserver(void);CLiSiObserver(void);void Update(string context); string GetName();private:void ReportToQinShiHuang(string report);/LiSiObs

9、erver.cpp#include StdAfx.h #include LiSiObserver.h #include using std:cout;using std:endl; using std:string;CLiSiObserver:CLiSiObserver(void) : IObserver(CLiSiObserver:CLiSiObserver(void)void CLiSiObserver:Update( string context )cout 活动，开始向汇报了. ReportToQinShiHuang(context);cout ：汇报完毕，秦赏给他两个萝卜吃吃. en

10、dl;void CLiSiObserver:ReportToQinShiHuang( string report )cout report.c_str() endl;：，秦！string CLiSiObserver:GetName()return m_name;/ZhouSiObserver.h#pragma once#include iobserver.h#include using std:string;class CZhouSiObserver : public IObserverpublic:CZhouSiObserver(void);CZhouSiObserver(void); vo

11、id Update(string context); string GetName();private:void Cry(string report);/ZhouSiObserver.cpp#include StdAfx.h#include ZhouSiObserver.h #include using std:cout; using std:endl; using std:string;CZhouSiObserver:CZhouSiObserver(void) : IObserver(CZhouSiObserver:CZhouSiObserver(void)void CZhouSiObser

12、ver:Update( string context )cout 活动，自己也开始活动了. Cry(context);cout ：真真的哭列了. endl;void CZhouSiObserver:Cry( string report )cout ：为因 report.c_str() , 所以我悲伤呀！ endl;string CZhouSiObserver:GetName()return m_name;/ Observer.cpp #include stdafx.h#include HanFeiZi.h#include LiSi.h#include HanFeiZiNew.h #includ

13、e HanFeiziObservable.h #include LiSiObserver.h #include ZhouSiObserver.h #include using std:cout; using std:endl;using std:string;void D()/IHanFeiZi.h, HanFeiZiNew.h, ILiSi.h, LiSi.h/ cout -用新的方法试试 endl;/CHanFeiZiNew hanfeizi;/hanfeizi.HaveBreakfast();/hanfeizi.HaveFun();void DNew()/IObservable.h, HanfeiziObservable.h, IObserver.h, LiSiObserver.h cout -用更新的方法再试试 AddObservpHanFeiZi-AddObservLiSi);ZhouSi);pHanFeiZi-HaveBreakfast();delete pLiSi; pLiSi = NULL;delete pHanFeiZi;pHanFeiZi = NULL;_tmain(argc, _TCHA