中文摘要：

介绍了利用ObjectARX. NET对AutoCAD二次开发的基本技术的概述。针对ObjectARX. NET开发工具的特点，介绍了CAD二次开发对图形数据库的访问技术，着重探讨了动态块技术在CAD二次开发中的应用。程序通过识别块体参数名修改相应的参数值实现了对动态块参照的修改，在参数化数据文件的组织和读取中，根据信息参数化的思想组织数据文件。程序采用基于关键字的方式读取相关数据便于数据文件进行扩充，并把这些技术应用到冷却塔软件开发出图程序中，实现冷却塔程序参数化和快速化设计，提高设计人员的工作效率。

英文摘要：

Introduce the basic technique of CAD secondary development on the basis of ObjectARX. NET. For the features of Object-ARX. NET development tool,introduce the technique of using CAD secondary development to access to graphical database,especially ex-plore the application of dynamic blocks in CAD secondary development. The program can recognize the name of dynamic block and mod-ify the corresponding parameter value,thus modifying the reference of dynamic block. The program organizes data files according to the thinking of transferring information to parameters,and reads corresponding data through keywords,making it convenient to extend the da-ta files. All these methods and techniques can be applied in cooling tower software to develop the diagram program. Thus designers can work efficiently as the realization of cooling tower software program parametric and rapid design.