C++设计模式学习之策略模式

Strategy:行为模式

封装算法：为所有的算法提供一个抽象的算法接口，并通过继承该抽象接口对所有的算法加以封装和实现。
具体的算法选择交由客户端决定。把公共代码提取公因式到父类

#include<stdlib.h>#include<iostream>using namespace std;class Strategy{public:virtual void SymEncrypt() = 0;};class Des :public Strategy{public:virtual void SymEncrypt(){cout << "使用DES加密" << endl;}};class AES :public Strategy{public:virtual void SymEncrypt(){cout << "AES加密" << endl;}};class Context{public:Context(Strategy *s){p = s;}void Operate(){p->SymEncrypt();}protected:private:Strategy *p;};void main(){//Strategy *s = NULL;//s = new AES;//s->SymEncrypt();//delete s;Strategy *s = NULL;Context *ctx = NULL;s = new AES;ctx = new Context(s);ctx->Operate();delete s;delete ctx;system("pause");}