//订阅者基类
class ISubscriber
{
public:ISubscriber(string name);virtual void update(string strMsg) = 0;  //更新订阅者自身状态，由发布者调用virtual ~ISubscriber(){};
protected:string m_name;    //订阅者名称
};ISubscriber::ISubscriber(string name) : m_name(name)
{
}//发布者基类
class IPublisher
{
public:virtual void add(ISubscriber *pObserver) = 0;    //增加订阅者virtual void remove(ISubscriber *pObserver) = 0; //移除订阅者virtual void notify() = 0;                       //通知订阅者virtual ~IPublisher(){};void setMsg(string strMsg);string getMsg();
protected:std::list<ISubscriber*> m_listObserver;          //保存所有订阅者的列表string m_strMsg;                                 //发布者发布的消息
};void IPublisher::setMsg(string strMsg)
{m_strMsg = strMsg;
}string IPublisher::getMsg()
{return m_strMsg;
}//发布者的实现类
class PublisherImpl : public IPublisher
{
public:virtual void add(ISubscriber *pObserver);virtual void remove(ISubscriber *pObserver);virtual void notify();~PublisherImpl();};void PublisherImpl::add(ISubscriber *pObserver)
{std::list<ISubscriber*>::iterator iter = find(m_listObserver.begin(), m_listObserver.end(), pObserver);if (iter == m_listObserver.end()){m_listObserver.push_back(pObserver);}
}void PublisherImpl::remove(ISubscriber *pObserver)
{std::list<ISubscriber*>::iterator iter = find(m_listObserver.begin(), m_listObserver.end(), pObserver);if (iter != m_listObserver.end()){m_listObserver.erase(iter);}
}void PublisherImpl::notify()
{std::list<ISubscriber*>::iterator iter;for (iter = m_listObserver.begin(); iter != m_listObserver.end(); ++iter){(*iter)->update(m_strMsg);}
}PublisherImpl::~PublisherImpl()
{std::list<ISubscriber*>::iterator iter, temp;for (iter = m_listObserver.begin(); iter != m_listObserver.end(); ++iter){temp = iter;delete (*temp);}m_listObserver.clear();
}//订阅者的实现类一
class CSDNSubscriber : public ISubscriber
{
public:CSDNSubscriber(string name);virtual void update(string strMsg);
};CSDNSubscriber::CSDNSubscriber(string name) : ISubscriber(name)
{
}void CSDNSubscriber::update(string strMsg)
{cout<<strMsg<<", 请关闭CSDN，停止上网，开始认真工作!"<<endl;
}//订阅者的实现类二
class ChatSubscriber : public ISubscriber
{
public:ChatSubscriber(string name);virtual void update(string strMsg);
};ChatSubscriber::ChatSubscriber(string name) : ISubscriber(name)
{
}void ChatSubscriber::update(string strMsg)
{cout<<strMsg<<", 请停止聊天，开始认真工作!"<<endl;
}int _tmain(int argc, _TCHAR* argv[])
{IPublisher *pSubject = new PublisherImpl;ISubscriber *pSubscriber = NULL;pSubscriber = new CSDNSubscriber("张三");  //向发布者中注册订阅者pSubject->add(pSubscriber);pSubscriber = new ChatSubscriber("李四");pSubject->add(pSubscriber);pSubscriber = new ChatSubscriber("王五");pSubject->add(pSubscriber);pSubject->setMsg("主管回来了");pSubject->notify();                    //发布者通知所有订阅者return 0;
}