c++ 设计模式之 抽象工厂模式

概念：

抽象工厂模式提供了一个创建相似或相关相互依赖的对象，而不需要说明其具体的实现.

类结构图：

图来自： wiki

示例代码：

#include <iostream>

class Button
{
public:
	virtual void paint() = 0;
};

class WinButton : public Button 
{
public:
	void paint (){
		std::cout << " Window Button \n";
	}
};

class MacButton : public Button 
{
public:
	void paint (){
		std::cout << " Mac Button \n";
	}
};

class ScrollBar 
{
public:
	virtual void paint() = 0;
};

class WinScrollBar : public ScrollBar 
{
public:
	void paint (){
		std::cout << " Window ScrollBar \n";
	}
};

class MacScrollBar : public ScrollBar {
public:

	void paint (){
		std::cout << " Mac ScrollBar \n";
	}
};


class GUIFactory 
{
public:
	virtual Button* createButton () = 0;
	virtual ScrollBar* createScrollBar () = 0;
};

class WinFactory : public GUIFactory 
{
public:
	Button* createButton (){
		return new WinButton;
	}
	ScrollBar* createScrollBar (){
		return new WinScrollBar;
	}
};

class MacFactory : public GUIFactory 
{
public:
	Button* createButton (){
		return new MacButton;
	}
	ScrollBar* createScrollBar (){
		return new MacScrollBar;
	}
};

int main()
{
	GUIFactory* guiFactory;
	Button *btn;
	ScrollBar *sb;

	guiFactory = new MacFactory;
	btn = guiFactory->createButton();
	btn -> paint();
	sb = guiFactory->createScrollBar();
	sb -> paint();

	guiFactory = new WinFactory;
	btn = guiFactory->createButton();
	btn -> paint();
	sb = guiFactory->createScrollBar();
	sb -> paint();

	return 0;
}