Studies On Extracting Entity Data From AutoCAD And Creating The Specialized Drawing Library Of Structural Design

With information technology developed at top speed, CAD is covered with the whole field of engineering design gradually. In the face of bulk work in design course, they have become cried for resolving problems which are realizing parameterization design according to projects needs, reuse element of CAD drawing and development. And self meaning of CAD is "Computer Aided Design" . If it couoldn't be developed and applied, it will be severe waste of resources. So, it is one of the most practical and convenient methods at present which is doing coherent work by using development tools of AutoCAD system providing. AutoCAD system provides five main development tools now: AutoLISP/Visual LISP, Object-ARX of using C++, Active X development of VB/VBA, ADS and development tool of Dot NET. Whereas AutoLISP/Visual LISP has high practicability to structural design, the language and DCL language will be researched the subject. The aims of this paper as follow: Extract entity data belongs to AutoCAD parameterization design, which is the most basic and important aspect. And technologists can do kinds of different demand work by extracting entity data; Creating the specialized drawing library will be researched in order to increase of the efficiency of structural design, reuse and decrease of repeat work.The study of extracting entity data is based on the complicated drawing of AutoCAD. Complicated drawing of AutoCAD includes a lot of entity data. Entity data includes data of entity set-up format, type of lines data and coordinate data and so on. The correct and reliable program of extracting the basic entity data of AutoCAD drawing has been proposed by using of the inner programming language of AutoLISP .The program has been implemented successfully in AutoCAD 2004 and more advanced versions. The study of creating the specialized drawing library of structural design is based on the methods of the parameterization drawing. The steps of the work are that: firstly, creating many basic graphics files in common use of structural design; secondly, using language of DCL to compose the program of interface dialog box of drawing library; thirdly, using the programming language of AutoLISP to compose correct and reliable driver program of dialog box of drawing library. The drawing library has been implemented successfully in AutoCAD 2004 and more advanced versions.