C++设计模式之观察者模式

1 观察者：

#include "Watcher.h"


Watcher::Watcher(string name)
{
    this->name=name;
}
Watcher::Watcher(const Watcher &watcher)//必须实现拷贝构造函数，才能放到容器里
{
    this->name=watcher.name;
}

Watcher::~Watcher(void)
{
}
string Watcher::getname()
{

    return name;
}
void Watcher::update()
{
    std::cout<<name+" is updated"<<endl;
}

2 主题

#include "Watched.h"
Watched::Watched(void)
{
}
Watched::~Watched(void)
{
}
void Watched::AddWatcher(Watcher *newone)
{
    allwatchers.push_back(*newone);

}
void Watched::RemoveWatcher(Watcher *oldone)
{
    for(int i=0;i<allwatchers.size();i++)
    {
        if(allwatchers[i].getname()==oldone->getname()) 
        {allwatchers.erase( allwatchers.begin()+ i ); break;}
    }
    
}
void Watched::RemoveAllWatcher()
{
    allwatchers.clear();
}
void Watched::NotifyAllWatcher()
{
    for(int i=0;i<allwatchers.size();i++)
    {
        allwatchers[i].update();
        
    }
}

3 main函数

// Observer.cpp : 定义控制台应用程序的入口点。
//
#include "vld.h"
#include "stdafx.h"
#include "Watched.h"
#include "Watcher.h"

int _tmain(int argc, _TCHAR* argv[])
{
    Watcher* Watcher1=new Watcher("Watcher1");
    Watcher* Watcher2=new Watcher("Watcher2");
    Watcher* Watcher3=new Watcher("Watcher3");
    Watched* watched=new Watched();
    watched->AddWatcher(Watcher1);
    watched->AddWatcher(Watcher2);
    watched->AddWatcher(Watcher3);
    watched->NotifyAllWatcher();
    getchar();
    delete watched;
    delete Watcher1;
    delete Watcher2;
    delete Watcher3;
    return 0;
}

4 运行效果