网上找的，不是自己写的
放上链接
blog.csdn.net/lcl_data/article/details/9208561
observer.cpp
#include <iostream>
#include <vector>
#include <string>
using namespace std;
class Secretary;
// 看股票的同事类（观察对象，观察者）
class StockObserver
{
public:
StockObserver(string strName, Secretary* strSub)
{ name = strName; sub = strSub; }
void Update();
private:
string name;
Secretary* sub;
};
// 秘书类（主题对象，通知者）
class Secretary
{
public:
string action;
void Add(StockObserver ob) {
observers.push_back(ob);
} void Remove(int addIndex) {
if(addIndex >=0 && addIndex < observers.size()) observers.erase(observers.begin() + addIndex); }
void Notify() {
vector<StockObserver>::iterator it;
for (it=observers.begin(); it!=observers.end(); ++it)
{ (*it).Update(); }
}
private:
vector<StockObserver>observers;
};
void StockObserver::Update()
{
cout << name << " : " << sub->action << ", begin to work" << endl;
}
int main()
{
// 创建通知者
Secretary* p = new Secretary();
// 观察者
StockObserver* s1 = new StockObserver("Lazy", p);
StockObserver* s2 = new StockObserver("SnowFire", p);
// 加入通知队列
p->Add(*s1);
p->Add(*s2);
// 事件
p->action = "The boss is coming...";
// 通知
p->Notify();
// 动态删除
p->Remove(0);
p->Notify();
return 0;
}
编译:make observer
