感觉抽象工厂模式有点像你去买电脑的时候，先告诉卖电脑的你要买联想的，然后再告诉卖电脑的你要个鼠标，最后你喜提联想的鼠标回家了。
这里也感谢菜鸟教程，提供免费的学习资料。
优点：当一个产品族中的多个对象被设计成一起工作时，它能保证客户端始终只使用同一个产品族中的对象。
缺点：产品族扩展非常困难，要增加一个系列的某一产品，既要在抽象的 Creator 里加代码，又要在具体的里面加代码。
使用场景： 1、QQ 换皮肤，一整套一起换。 2、生成不同操作系统的程序。
注意事项：产品族难扩展，产品等级易扩展。
根据上面的UML图编码：
color.h
#ifndef _COLOR_
#define _COLOR_
#include "iostream"
using namespace std;
class color
{
public:
virtual void fill() = 0;
};
class red:public color
{
public:
void fill()
{
cout << "fill red." << endl;
}
};
class green:public color
{
public:
void fill()
{
cout << "fill green." << endl;
}
};
class blue:public color
{
public:
void fill()
{
cout << "fill blue." << endl;
}
};
#endif
shape.h
#ifndef _SHAPE_
#define _SHAPE_
#include "iostream"
using namespace std;
class shape
{
public:
virtual void draw() = 0;
};
class circle:public shape
{
public:
void draw()
{
cout << "draw circle." << endl;
}
};
class square:public shape
{
public:
void draw()
{
cout << "draw square." << endl;
}
};
class rectangle:public shape
{
public:
void draw()
{
cout << "draw rectangle." << endl;
}
};
#endifabstract_factory.h
#ifndef _ABSTRACT_FACTORY_
#define _ABSTRACT_FACTORY_
#include "color.h"
#include "shape.h"
#include "iostream"
#include "string"
using namespace std;
class abstract_factory
{
public:
virtual shape* get_shape(string shape_type) = 0;
virtual color* get_color(string specific_color) = 0;
};
class shape_factory:public abstract_factory
{
public:
shape* get_shape(string shape_type)
{
if (shape_type == "CIRCLE")
return new circle;
else if (shape_type == "SQUARE")
return new square;
else if (shape_type == "RECTANGLE")
return new rectangle;
else
{
cout << "there is no such shape." << endl;
return NULL;
}
}
color* get_color(string specific_color)
{
return NULL;
}
};
class color_factory:public abstract_factory
{
public:
color* get_color(string specific_color)
{
if (specific_color == "RED")
return new red;
else if (specific_color == "GREEN")
return new green;
else if (specific_color == "BLUE")
return new blue;
else
{
cout << "there is no such color." << endl;
return NULL;
}
}
shape* get_shape(string shape_type)
{
return NULL;
}
};
class factory_producer
{
public:
abstract_factory* get_factory(string factory_type)
{
if (factory_type == "SHAPE")
return new shape_factory;
else if (factory_type == "COLOR")
return new color_factory;
else
{
cout << "there is no such factory." << endl;
return NULL;
}
}
};
#endif
abstract_factory_mode.cpp
#include "iostream"
#include "string"
#include "string.h"
#include "color.h"
#include "shape.h"
#include "abstract_factory.h"
using namespace std;
int main(int argc, char const *argv[])
{
factory_producer f_p;
abstract_factory *fac = NULL;
shape *t_s = NULL;
color *t_c = NULL;
fac = f_p.get_factory("SHAPE");
if (fac != NULL)
{
t_s = fac->get_shape("CIRCLE");
if (t_s != NULL)
{
t_s->draw();
delete t_s;
t_s = NULL;
}
t_s = fac->get_shape("SQUARE");
{
t_s->draw();
delete t_s;
t_s = NULL;
}
}
delete fac;
fac = NULL;
fac = f_p.get_factory("COLOR");
if (fac != NULL)
{
t_c = fac->get_color("RED");
if (t_c != NULL)
{
t_c->fill();
delete t_c;
t_c = NULL;
}
t_c = fac->get_color("WHITE");
if (t_c != NULL)
{
t_c->fill();
delete t_c;
t_c = NULL;
}
}
delete fac;
fac = NULL;
return 0;
}
打印效果
这里做个小笔记
抽象类无法实例化对象，当时可给我郁闷的呀，我这不是抽象类呀，我实例化的明明是派生类，搞什么鬼噢？！
度娘真相了，百度到一篇大佬的csdn帖子
记住：如果你的抽象类的派生类有任何一个纯虚函数没有实现，那么不管其它做的再多，这个类仍然是一个抽象类。
abstract_factory是一个抽象类，然而我写派生类shape_factory和color_factory的时候并没有实现与它本身不想关的虚函数。