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; } |
