#include "concrete_subject.h"

#include "concrete_observer.h"

#ifndef SAFE_DELETE

#define SAFE_DELETE(p) { if(p){delete(p); (p)=NULL;} }

#endif

int main()

{

// 创建主题、观察者

ConcreteSubject *pSubject = new ConcreteSubject();

IObserver *pObserver1 = new ConcreteObserver("Jack Ma");

IObserver *pObserver2 = new ConcreteObserver("Pony");

// 注册观察者

pSubject->Attach(pObserver1);

pSubject->Attach(pObserver2);

// 更改价格，并通知观察者

pSubject->SetPrice(12.5);

pSubject->Notify();

// 注销观察者

pSubject->Detach(pObserver2);

// 再次更改状态，并通知观察者

pSubject->SetPrice(15.0);

pSubject->Notify();

SAFE_DELETE(pObserver1);

SAFE_DELETE(pObserver2);

SAFE_DELETE(pSubject);

getchar();

return 0;

}