设计模式之外观模式

#include<iostream>

//电脑的例子更形象：
//电脑整机是 CPU、内存、硬盘的外观。有了外观以后，启动电脑和关闭电脑都简化了。
//直接 new 一个电脑。
//在 new 电脑的同时把 cpu、内存、硬盘都初始化好并且接好线。
//对外暴露方法（启动电脑，关闭电脑）。
//启动电脑（按一下电源键）：启动CPU、启动内存、启动硬盘
//关闭电脑（按一下电源键）：关闭硬盘、关闭内存、关闭CPU

//硬件基类
class Hardware {
public:
    virtual void Open() = 0;
    virtual void Close() = 0;
};

//cpu
class Cpu : public Hardware {
public:
    //实现细节
    void Open()override {
    
        std::cout << "cpu is open !\n";
    }
    void Close()override {
        std::cout << "cpu is close !\n";
    }
};

//内存
class Memory : public Hardware {
public:
    //实现细节
    void Open()override {

        std::cout << "memory is open!\n";
    }
    void Close()override {
        std::cout << "memory is close !\n";
    }
};

//硬盘
class HardDisk : public Hardware {
public:
    //实现细节
    void Open()override {

        std::cout << "harddisk is open!\n";
    }
    
    void Close()override {
        std::cout << "harddisk is close !\n";
    }
};

//主机外观 
class Computer {
private:
    //主机所拥有的硬件
    Hardware* cpu;
    Hardware* memory;
    Hardware* hardDisk;
public:
    Computer() {
        //装机 。。给电脑装配硬件
        cpu = new Cpu();
        memory = new Memory();
        hardDisk = new HardDisk();
    }
    void Open() {
        cpu->Open();
        memory->Open();
        hardDisk->Open();
        std::cout << "已开机\n";
    }
    void Close(){
        cpu->Close();
        memory->Close();
        hardDisk->Close();
        std::cout << "已关机\n";
    }
};

int main()
{
    //组装电脑
    Computer* computer = new Computer;
    //打开电脑
    computer->Open();
    //关闭电脑
    computer->Close();
    system("pause");

    return 0;
}