这两天做MVC，其中有OBSERVER模式的应用，简单实现了下接口。
Subject.h
#ifndef _SUBJECT_H
#define _SUBJECT_H
#include “Observer.h”
#define MAX_OBSERVER_NUM 10
class Subject
{
public:
virtual ~Subject();
virtual void Attach(Observer *pObserver);
virtual void Detach(Observer *pObserver); // 未实现
virtual void Notify();
protected:
Subject(int m = MAX_OBSERVER_NUM);
private:
Observer **ppObserver;
int max;
int size;
};
#endif
Subject.cpp
#include “Subject.h”
Subject::Subject(int m) : max(m), size(0)
{
ppObserver = new Observer*[max];
}
Subject::~Subject()
{
if(ppObserver)
delete [] ppObserver;
}
void Subject::Attach(Observer *pObserver)
{
if(size >= max)
return;
ppObserver[size++] = pObserver;
}
void Subject::Detach(Observer *pObserver)
{
return;
}
void Subject::Notify()
{
for(int i = 0; i < size; i++)
ppObserver[i]->Update(this);
}
Observer.h
#ifndef _OBSERVER_H
#define _OBSERVER_H
class Subject; // Subject的向前声明
class Observer
{
public:
virtual ~Observer() {};
virtual void Update(Subject* pSubject) = 0; // 子类必须实现的方法
protected:
Observer() {}; // 仅由子类调用
};
#endif
