Abstract Factory(抽象工廠模式) _after

最新推荐文章于 2025-11-13 13:32:52 发布

转载最新推荐文章于 2025-11-13 13:32:52 发布 · 50 阅读

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CC 4.0 BY-SA版权

原文链接：http://www.cnblogs.com/jerry550409/archive/2009/02/19/1393572.html

本文通过一个具体的工厂模式实现示例，展示了如何根据不同条件创建不同类型的界面组件，如按钮和菜单等，并通过预编译指令实现了运行时的选择。

# include <iostream>
using namespace std;

#define WINDOWS

class Widget {
public:
   virtual void draw() = 0;
};

class MotifButton : public Widget {
public:
   void draw() { cout << "MotifButton\n"; }
};
class MotifMenu : public Widget {
public:
   void draw() { cout << "MotifMenu\n"; }
};

class WindowsButton : public Widget {
public:
   void draw() { cout << "WindowsButton\n"; }
};
class WindowsMenu : public Widget {
public:
   void draw() { cout << "WindowsMenu\n"; }
};

class Factory {
public:
   virtual Widget* create_button() = 0;
   virtual Widget* create_menu() = 0;
};

class MotifFactory : public Factory {
public:
   Widget* create_button() {
      return new MotifButton; }
   Widget* create_menu()   {
      return new MotifMenu; }
};

class WindowsFactory : public Factory {
public:
   Widget* create_button() {
      return new WindowsButton; }
   Widget* create_menu()   {
      return new WindowsMenu; }
};

Factory* factory;

void display_window_one() {
   Widget* w[] = { factory->create_button(),
                   factory->create_menu() };
   w[0]->draw();  w[1]->draw();
}

void display_window_two() {
   Widget* w[] = { factory->create_menu(),
                   factory->create_button() };
   w[0]->draw();  w[1]->draw();
}

int main( void ) {
#ifdef MOTIF
   factory = new MotifFactory;
#else // WINDOWS
   factory = new WindowsFactory;
#endif

   Widget* w = factory->create_button();
   w->draw();
   display_window_one();
   display_window_two();
}

// WindowsButton
// WindowsButton
// WindowsMenu
// WindowsMenu
// WindowsButton

转载于:https://www.cnblogs.com/jerry550409/archive/2009/02/19/1393572.html