Abstract
AutoCAD is software developed by Autodesk Inc., an American company. It is the most widely used, aided drawing and design software now. However, it will be complicated for users to use it for intelligent graphic design to complete a specific object design because it is common software. Therefore, AutoCAD allows users develop it into the AutoCAD-based secondary development system, which meets the designer's need and is adapted to the graphics features and graphics requirements. According to the characteristics of graphic design in different fields, various graphics units can be constructed by analyzing graphics functions and graphics features. Furthermore, a graphics software base on graphics units can be developed using the secondary Development function of AutoCAD. It can be envisaged that designers can directly draw the corresponding component graphics if the components often used are designed as graphics units on the basis of the categories, which will provide the designer a great deal of convenience.
This thesis describes the development of building electricity graphics design software which is comprise of two main sections, basic graphics tools and specialized graphics tools. Since time is limited, only line, circle and polyline are developed in basic graphics tool, and only resistor and switch are developed in specialized graphics tool.
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Keywords: AutoCAD VB ActiveX Automation the secondary development
