设计模式学习之----策略模式

策略模式：定义一系列的算法，把它们一个个封装起来，并且使它们可相互替换。接口和实现进行了隔离。

大体实现：基类定义接口子类实现算法，运用多态，运行时调用不同的算法。

#include <iostream>
#include <string>

using namespace std;
class Strategy
{
public:
    virtual void crypt() = 0;
};

class AES :public Strategy
{
public:
    virtual void crypt()
    {
        cout << "AES加密算法" << endl;
    }
};

class DES :public Strategy
{
public:
    virtual void crypt()
    {
        cout << "DES加密算法" << endl;
    }
};

//编程的对象，涉及的接口都依赖于抽象
class Context
{
public:
    void setStrategy(Strategy *strategy)
    {
        m_strategy = strategy;
    }
    void myOperator()
    {
        m_strategy->crypt();
    }
private:
    Strategy *m_strategy;
};


int main()
{
    Context *context = new Context; //编程对象
    Strategy *strategy = nullptr;
    strategy = new AES;
    context->setStrategy(strategy);
    context->myOperator();
    delete context;
    delete strategy;
    return system("pause");
}