C++装饰者模式

矫情吗；* 2022-09-17 04:22 134阅读 0赞

头文件：

#ifndef CDECORATORMODE_H
    #define CDECORATORMODE_H
    #include<QDebug>
    #include <iostream>
    #include<string>
    using namespace std;
    
    
    #define cout qDebug() << "[" << __FILE__ << ":" << __LINE__ << ":" << __func__ << "]"
    
    /*
     * 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，Decorator模式相比生成子类更为灵活。
     */
    
    
    
    class CDecoratorMode
    {
        
    public:
        CDecoratorMode();
    };
    
    //成绩单抽象基类
    class ISchoolReport
    {
        
    public:
        ISchoolReport(void)
        {
        
        }
        virtual ~ISchoolReport(void)
        {
        
        }
        virtual void Report() = 0;
        virtual void Sign(string name) = 0;
    };
    //四年级成绩单
    class CFouthGradeSchoolReport :
        public ISchoolReport
    {
        
    public:
        CFouthGradeSchoolReport(void);
        ~CFouthGradeSchoolReport(void);
        void Report();
        void Sign(string name);
    };
    
    
    //成绩单装饰基类
    class CReportDecorator :
        public ISchoolReport
    {
        
    public:
        CReportDecorator(ISchoolReport *psr);
        virtual ~CReportDecorator(void);
        void Report();
        void Sign(string name);
    private:
        ISchoolReport *m_pSchoolReport;
    };
    
    
    //成绩排名装饰者
    class CSortDecorator :
        public CReportDecorator
    {
        
    public:
        CSortDecorator(ISchoolReport *psr);
        ~CSortDecorator(void);
        void Report();
    private:
        void ReportSort();
    };
    
    
    //最高分装饰者
    class CHighScoreDecorator :
        public CReportDecorator
    {
        
    public:
        CHighScoreDecorator(ISchoolReport *psr);
        ~CHighScoreDecorator(void);
        void Report();
    private:
        void ReportHighScore();
    };
    
    int DecoratorTest();
    
    
    
    #endif // CDECORATORMODE_H

源文件：

#include "cdecoratormode.h"
    
    CDecoratorMode::CDecoratorMode()
    {
        
    
    }
    CFouthGradeSchoolReport::CFouthGradeSchoolReport(void)
    {
        
    }
    CFouthGradeSchoolReport::~CFouthGradeSchoolReport(void)
    {
        
    }
    void CFouthGradeSchoolReport::Report()
    {
        
        cout << "尊敬的XXX家长：" << endl;
        cout << "......" << endl;
        cout << "语文62  数学65  体育98  自然63" << endl;
        cout << "......" << endl;
        cout << "                家长签名：" << endl;
    }
    void CFouthGradeSchoolReport::Sign(string name)
    {
        
        cout << "家长签名为：" << name.c_str() << endl;
    }
    
    CReportDecorator::CReportDecorator(ISchoolReport *psr)
    {
        
        this->m_pSchoolReport = psr;
    }
    CReportDecorator::~CReportDecorator(void)
    {
        
    }
    void CReportDecorator::Report()
    {
        
        this->m_pSchoolReport->Report();
    }
    void CReportDecorator::Sign( string name )
    {
        
        this->m_pSchoolReport->Sign(name);
    }
    CHighScoreDecorator::CHighScoreDecorator( ISchoolReport *psr ) : CReportDecorator(psr)
    {
        
    }
    CHighScoreDecorator::~CHighScoreDecorator(void)
    {
        
    }
    void CHighScoreDecorator::Report()
    {
        
        this->ReportHighScore();
        this->CReportDecorator::Report();
    }
    void CHighScoreDecorator::ReportHighScore()
    {
        
        cout << "这次考试语文最高是75， 数学是78， 自然是80" << endl;
    }
    
    CSortDecorator::CSortDecorator( ISchoolReport *psr ) : CReportDecorator(psr)
    {
        
    }
    CSortDecorator::~CSortDecorator(void)
    {
        
    }
    void CSortDecorator::ReportSort()
    {
        
        cout << "我是排名第38名..." << endl;
    }
    void CSortDecorator::Report()
    {
        
        this->CReportDecorator::Report();
        this->ReportSort();
    }
    //使用测试
    static void DoIt()
    {
        
        ISchoolReport *psr = new CFouthGradeSchoolReport();
        psr->Report();//看成绩单
        psr->Sign("老三");//很开心，就签字了
        delete psr;
    }
    static void DoNew()
    {
        
        cout << "----------分部分进行装饰----------" << endl;
        ISchoolReport *psr = new CFouthGradeSchoolReport();//原装成绩单
    
        ISchoolReport *phsr = new CHighScoreDecorator(psr);//加了最高分说明的成绩单
        ISchoolReport *pssr = new CSortDecorator(phsr);//又加了成绩排名的说明
        pssr->Report();//看成绩单
        pssr->Sign("老三");//很开心，就签字了
    
        //先装饰哪个不重要，顺序已经在装饰内部确定好，但一定要调用最后一个装饰器的接口。
        //ISchoolReport *phsr = new CHighScoreDecorator(psr);//加了最高分说明的成绩单
        //ISchoolReport *pssr = new CSortDecorator(phsr);//又加了成绩排名的说明
        //pssr->Report();//看成绩单
        //pssr->Sign("老三");//很开心，就签字了
    
        delete pssr;
        delete phsr;
        delete psr;
    }
    int DecoratorTest()
    {
        
        //在装饰之前，可以用继承的办法，来进行简单的修饰
    //    DoIt();
    
        //但如果需要修饰的项目太多呢？或者装饰的项目不是固定的，继承显然会变得更复杂
        DoNew();
        return 0;
    }