c++ 設計模式之 抽象工廠模式

概念：

抽象工廠模式提供了一個創建相似或相關相互依賴的對象，而不需要說明其具體的實現.

示例代碼：

[cpp] 
#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; 
}