《Head First 设计模式》C++实现【策略模式(Strategy Pattern)】

摘要

《Head First 设计模式》书中第2章——策略模式(Strategy Pattern)的C++代码实现。
策略模式(Strategy Pattern)：定义了算法簇，分别封装起来，让他们之间可以相互替换，此模式让算法的变化独立于使用算法的客户。

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实现代码

//《Head First 设计模式》C++实现【策略模式(Strategy Pattern)】
// 定义了算法簇，分别封装起来，让他们之间可以相互替换，此模式让算法的变化独立于使用算法的客户。
#include <iostream>
using namespace std;

//接口
class CFlyBehavior
{
public:
	virtual void Fly() = 0;
};
class CQuackBehavior
{
public:
	virtual void Quack() = 0;
};
class CDuck
{
public:
	CFlyBehavior  *p_fly_behavior;
	CQuackBehavior  *p_quack_behavior;
	
	virtual void Display() = 0;//every ducks is different
	void Swim()
	{
		printf("All duck able to swiming.\n");
	}
	
	void PerformFly()
	{
		p_fly_behavior->Fly();
	}
	void PerformQuack()
	{
		p_quack_behavior->Quack();
	}
	void SetFlyBehavior(CFlyBehavior  *p_fly_behavior)
	{
		this->p_fly_behavior = p_fly_behavior;
	}
	void SetQuackBehavior(CQuackBehavior  *p_quack_behavior)
	{
		this->p_quack_behavior = p_quack_behavior;
	}
	//  鸭子的其他方法……

};


//行为对象
class CFlyWithWings : public CFlyBehavior
{
public:
	 void Fly() override
	{
		printf("I'm flying!!\n");
	}

};
class CFlyNoWay : public CFlyBehavior
{
public:
	void Fly() override
	{
		printf("I can't flying.\n");
	}

};
class CQuack : public CQuackBehavior
{
public:
	void Quack() override
	{
		printf("Quack quack quack ...\n");
	}

};
class CSQuack : public CQuackBehavior
{
public:
	void Quack() override
	{
		printf("Squack squack squack ...\n");
	}

};
class CMuteQuack : public CQuackBehavior
{
public:
	void Quack() override
	{
		
	}

};

//鸭子对象
//绿头鸭
class CMallarDuck : public CDuck
{
public:
	CMallarDuck()
	{
		this->p_fly_behavior = new CFlyNoWay();
		this->p_quack_behavior = new CQuack();
	}
	void Display() override
	{
		printf("I am MallarDuck.\n");
	}
};
//橡皮鸭
class CRubberDuck : public CDuck
{
public:
	CRubberDuck()
	{
		this->p_fly_behavior = new CFlyNoWay();
		this->p_quack_behavior = new CSQuack();
	}
	void Display() override
	{
		printf("I am RubberrDuck.\n");
	}
};

int main()
{
	CDuck *p_mallar_duck = new CMallarDuck();
	CDuck *p_rubber_duck = new CRubberDuck();

	p_mallar_duck->Display();
	p_mallar_duck->Swim();
	p_mallar_duck->PerformFly();
	p_mallar_duck->PerformQuack();

	p_rubber_duck->Display();
	p_rubber_duck->Swim();
	p_rubber_duck->PerformFly();
	p_rubber_duck->PerformQuack();

	p_rubber_duck->SetFlyBehavior(new CFlyWithWings);
	p_rubber_duck->PerformFly();

	system("pause");
	return 0;
}

 

原文作者：Liber-coder

转载自：https://blog.csdn.net/a435262767/article/details/91047356