c++ 装饰模式(decorate)

  装饰模式:动态地给一个对象添加一些额外的职责。就增加功能来说,装饰模式相比生成子类 更为灵活。有时我们希望给某个对象而不是整个类添加一些功能。比如有一个手机,允许你为手机添加特性,比如增加挂件、屏幕贴膜等。一种灵活的设计方式是, 将手机嵌入到另一对象中,由这个对象完成特性的添加,我们称这个嵌入的对象为装饰。这个装饰与它所装饰的组件接口一致,因此它对使用该组件的客户透明。

 

 

#include <iostream>
#include <string>

using namespace std;

class Phone
{
public:
    Phone() {}
    virtual ~Phone() {}
    virtual void ShowDecorate() {} 
};

class iPhone:public Phone
{
private:
    string m_name;
public:
    iPhone(string name):m_name(name){}
    ~iPhone() {}
    void ShowDecorate()
    {
        cout << m_name << "的装饰" <<endl;
    }
};

class AndroidPhone : public Phone
{
private:
    string m_name;
public:
    AndroidPhone(string name):m_name(name){}
    ~AndroidPhone() {}
    void ShowDecorate()
    {
        cout << m_name << "的装饰" <<endl;
    }
};

class DecoratorPhone : public Phone
{
private:
    Phone *m_phone;
public:
    DecoratorPhone(Phone *phone):m_phone(phone) {}
    virtual void ShowDecorate()
    {
        m_phone->ShowDecorate();
    }
};

class DecoratorPhoneA:public DecoratorPhone
{
public:
    DecoratorPhoneA(Phone *phone) : DecoratorPhone(phone) {}
    void ShowDecorate() 
    {
        DecoratorPhone::ShowDecorate(); 
        AddDecorate();
    }
private:
    void AddDecorate()
    {
        cout << "增加挂件" << endl;
    }
};

int main()
{
     Phone *dpa = new DecoratorPhoneA(new iPhone("5s"));
     dpa->ShowDecorate();
     delete dpa;
    
     Phone *dpb = new DecoratorPhoneA(new AndroidPhone("Mi2s"));
     dpb->ShowDecorate();

     system("pause");
     return 0;
}

 

输出结果:

5s的装饰
增加挂件
Mi2s的装饰
增加挂件
请按任意键继续. . .

 

 

posted @ 2013-12-18 15:20  onlycxue  阅读(2189)  评论(0编辑  收藏  举报