观察者模式

观察者模式常用于事件通知。
observer.h

#pragma once

class IObserver
{
public:
	virtual ~IObserver(){}
	virtual void Doprogress(float percent) = 0;
};

class CObserverProgressBar : public IObserver
{
public:
	virtual ~CObserverProgressBar(){}
	virtual void Doprogress(float percent);
};

class CObserverConsole : public IObserver
{
public:
	virtual ~CObserverConsole(){}
	virtual void Doprogress(float percent);
};

observer.cpp

#include <iostream>
#include "Observer.h"

using namespace std;

void CObserverProgressBar::Doprogress(float percent)
{
	cout << "CObserverProgressBar:" << percent << endl; 
}

void CObserverConsole::Doprogress(float percent)
{
	cout << "CObserverConsole:" << percent << endl; 
}

eventCenter.h

#pragma once
#include <list>
#include "Observer.h"

class CEvent
{
	typedef std::list<IObserver*> OBSERVER_LIST;
	int m_sum;
	int m_dec;
	int m_times;
	OBSERVER_LIST m_observerList;
public:
	CEvent(int sum, int dec);
	virtual ~CEvent(){}
	void addObserver(IObserver* observer);
	void delObserver(IObserver* observer);
	void notify();
};

observer.cpp

#include <iostream>
#include "Observer.h"

using namespace std;

void CObserverProgressBar::Doprogress(float percent)
{
	cout << "CObserverProgressBar:" << percent << endl; 
}

void CObserverConsole::Doprogress(float percent)
{
	cout << "CObserverConsole:" << percent << endl; 
}

main.cpp

#include "EventCenter.h"
#include "Observer.h"

int main()
{
	CObserverProgressBar progrossBar;
	CObserverConsole consol;

	CEvent event(256, 8);
	event.addObserver(&progrossBar);
	event.addObserver(&consol);
	event.notify();

	event.delObserver(&progrossBar);
	event.delObserver(&consol);
	return 0;
}