抽象工厂举例

#ifndef PRODUCTA_H
#define PRODUCTA_H
#include <iostream>
using namespace std;

class ProductA{
public:
    virtual void say(){
        cout << "I'm A" << endl;
    }
};

class ProductA1:public ProductA{
public:
    void say(){
        cout << "I'm A1" << endl;
    }
};

class ProductA2:public ProductA{
public:
    void say(){
        cout << "I'm A2" << endl;
    }
};

#endif // PRODUCTA_H

#ifndef PRODUCTC_H
#define PRODUCTC_H
#include <iostream>
using namespace std;

class ProductC{
public:
    virtual void say(){
        cout << "I'm C" << endl;
    }
};

class ProductC1:public ProductC{
public:
    void say(){
        cout << "I'm C1" << endl;
    }
};

class ProductC2:public ProductC{
public:
    void say(){
        cout << "I'm C2" << endl;
    }
};
#endif // PRODUCTC_H

#ifndef PRODUCTFACTORY_H
#define PRODUCTFACTORY_H
#include "ProductA.h"
#include "ProductC.h"

class ProductFactory{
public:
    virtual ProductA* createProductA(){
        return new ProductA;
    }

    virtual ProductC* createProductC(){
        return new ProductC;
    }
};

class ProductFactory1:public ProductFactory{
public:
    ProductA* createProductA(){
        return new ProductA1;
    }
    ProductC* createProductC(){
        return new ProductC1;
    }
};

class ProductFactory2:public ProductFactory{
public:
    ProductA* createProductA(){
        return new ProductA2;
    }
    ProductC* createProductC(){
        return new ProductC2;
    }
};
#endif // PRODUCTFACTORY_H

#include "ProductFactory.h"

void test(ProductFactory &pf){
    ProductA* pa = pf.createProductA();
    ProductC* pc = pf.createProductC();
    pa->say();
    pc->say();
    delete pa;
    delete pc;
}

int main(){
    ProductFactory1 pf1;
    test(pf1);
    cout << "ProductFactory1 end,ProductFactory2 start" << endl;
    ProductFactory2 pf2;
    test(pf2);

    int i;
    cin >> i;

    return 0;
}