责任链

*****************************在上看到一篇责任链的文章，用c++给他重写一遍自己也学习下。
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class Handler {
protected:
 Handler *successor;
public:
 void SetSuccessor(Handler *suc) {
 successor = suc;
 }
 virtual void HandleRequest(int request) = 0;
};class Concretehandler1 :public Handler {
public:
 void HandleRequest(int request) {
 if (request > 0 && request < 20) {
 cout << "do 1" << endl;
 } else if (successor != NULL) {
 successor->HandleRequest(request);
 }
 }
};class Concretehandler2 :public Handler {
public:
 void HandleRequest(int request) {
 if (request > 20) {
 cout << "do 2" << endl;
 } else if (successor != NULL) {
 successor->HandleRequest(request);
 }
 }
};int _tmain(int argc, _TCHAR* argv[])
{
 Handler *h1 = new Concretehandler1;
 Handler *h2 = new Concretehandler2;
 Handler *h22 = new Concretehandler2;h1->SetSuccessor(h2);
 h2->SetSuccessor(h22);
 h22->SetSuccessor(NULL);int requests[] = {23,2,3};

 for (int i = 0;i < 3;i++) {
 h1->HandleRequest(requests[i]);
 cout << "**********" << endl;
 }
 system("pause");
}

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write by fgd