用C语言实现DWG格式信息的读取，不是用OPENdwg toolkit编的，自己定义的函数-DWG format, with the C language to read the information is not compiled with OPENdwg toolkit, and their defined functions

介绍了OpenDWG图形文件结构，针对其复杂的数据格式提供了一种基于OpenDWG Toolkit的DWG文件读取方法，并给出源代码！-the orgnization of OpenDWG,A method to read DWG file bansed OpenDWG ToolKit

OpenDWG Toolkit官方开发文档，比较详细，不过是英文的。-OpenDWG Toolkit official development documents, in more detail, but in English.