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;}