自己编写的CAD二次开发程序，采用objectARX，功能实现了遍历CAD中所有图层的（也可方便指定图层）的实体的扩展属性（即XData）,利用此程序可方便的提取出你所指定的对象！（本程序在objectARX2002下开发）-prepared by their CAD program, using objectARX. Traversing the realization of all CAD layer (which can also facilitate the designated lay