以电子版发布此书的目的是提高国内CAD开发者的普遍水平，让入门者更快地能够编

写代码，让初级程序员更快达到中高级程序员的水平。为国内CAD开发整体水平的提高，

我们愿意尽一份微薄之力。-Electronic release the book' s purpose is to improve the general level of domestic CAD developers, beginners to quickly be able to write code, so that the junior programmer to senior programmer level faster. Raising the overall level of domestic CAD development, we are willing to do modest.