cad 二次开发，读取配置文件（文件中有源与目标的块名）来更改块名。-autocad objectarx,read text file(include source blockname and destination blockname)that change the blockname

b-spline 生成代码，包含一个建立方形的算例-b-spline generation code, include one example which can generate square shape

测绘中常用的一些制图符号，以及内业展点程序。主要包括： 围墙、栏杆、道路、圆堤的定义绘制，坐标正算反算程序，读取文件在CAD中进行展点。(Some cartographic symbols used in surveying and mapping as well as internal exhibition procedures are presented. Mainly include: The definition of the fence, railings, roads, roun