用子类处理实现图标菜单

论述如何用子类处理方法，捕获Windows系统传递到窗口的命令，进而生成带自定义图标的菜单；同时封装一个复杂过程，允许原消息处理函数实际执行命令以简化代码。自定义类对象封装了任一菜单项自定义图标的绘制过程；菜单维护模块创建并管理自定义类对象的一系列实例，所有实例联合注册为用户自定义菜单。除菜单检测与绘制操作由用户自定义函数完成外，其他操作皆通过消息传递函数返回Windows系统。

Creating Icon Menu by Subclassing

This article demonstrates the process of subclassing your window in order to catch commands that are passed by the Windows OS to the window in which owner drawn menus have been created. Meanwhile a complex process is encapsulated to allow simple code in the actual implementation of the object. The user defined class object encapsulates the process of drawing each menu entry and the menu maintenance code module manages a list of instances created from user defined class object which represent each menu entry that has been registered as an owner drawn menu. Most of the operations call back to the Windows OS except the measuring and drawing model.