Strategy策略模式

#include <iostream>using namespace std;class IStrategy{public:IStrategy(void){}virtual ~IStrategy(void){}virtual void Operate(void) = 0;};class CContext{public:CContext(IStrategy *pStrategy){this->m_pStrategy = pStrategy;}~CContext(void){delete this->m_pStrategy;}void Operate(void){this->m_pStrategy->Operate();}private:IStrategy *m_pStrategy;};class CBackDoor : public IStrategy{public:void Operate(void){cout << "调用第一个锦囊" << endl;}};class CGivenGreenLight :public IStrategy{public:void Operate(void){cout << "调用第二个锦囊" << endl;}};class CBlockEnemy :public IStrategy{public:void Operate(void){cout << "调用第三个锦囊" << endl;}};int main(){CContext *pContext;pContext = new CContext(new CBackDoor());pContext->Operate();delete pContext;pContext = new CContext(new CGivenGreenLight());pContext->Operate();delete pContext;pContext = new CContext(new CBlockEnemy());pContext->Operate();delete pContext;IStrategy* ist  = new CBackDoor();//为什么不直接用这种？ist->Operate();return 0;}