序言

还是参考的菜鸟教程，会C++的还是看C++的方式来得舒服。

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理解

使用符合UML规范的便于理解和回忆，接口其实就是普通的基类

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源码

strategy.h

/// 策略class Strategy{public:    virtual ~Strategy();            virtual int operation(const int& num1, const int& num2) = 0;};/// 加策略class AddOperation : public Strategy{public:    int operation(const int &num1, const int &num2) override;};/// 减策略class SubtractOperation : public Strategy{public:    int operation(const int &num1, const int &num2) override;};/// 上下文class Context{public:        explicit Context(Strategy *strategy);    ~Context();    int operation(const int &num1, const int &num2);private:/// 所拥有的策略    Strategy *strategy = nullptr;};

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strategy.cpp

Strategy::~Strategy(){}int AddOperation::operation(const int &num1, const int &num2){    return num1 + num2;}int SubtractOperation::operation(const int &num1, const int &num2){    return num1 - num2;}Context::Context(Strategy *strategy)    : strategy(strategy){}Context::~Context(){    if (strategy)        delete strategy;}int Context::operation(const int &num1, const int &num2){    if (strategy)    {        return strategy->operation(num1, num2);    }    return INT_MIN;}

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使用的地方

std::shared_ptr< Context > context(new Context(new AddOperation));std::cout << context->operation(10, 5) << std::endl;context.reset(new Context(new SubtractOperation));std::cout << context->operation(10, 5) << std::endl;

不同策略则生成不同的对象给Context，Context会根据其拥有的策略进行运算。

来源地址：https://blog.csdn.net/SBKnight/article/details/132172760