Dwg Files Offline Browser Activex Control Study

As AutoCAD DWG graphic file is widely used in engineering design field and it is also a bridge between different CAD graphic files, viewing DWG files without AutoCAD is becoming more and more important. In this dissertation, a DWG viewer based on ActiveX is researched and developed.In the beginning, The significance of developing DWG viewer based on ActiveX control and the research achievement in the world are analyzed. Then, the blueprint and method of developing DWG Viewer is demonstrated. Some important problems involved with the development of DWG Viewer are studied in a thoroughly way.As DWG files is a binary file and its format is unknowable, how to get data from DWG files with ODT (OpenDWG Toolkit) and how to organize the program framework are thoroughly researched. All of these are very important to develop a DWG viewer in a short time.In fact, the procedure of viewing DWG file is the procedure of getting data from the file and utilizing the data to portray vector graphic. In this dissertation, the algorithms of graphics in DWG files are discussed. Part of the codes in C++ programming language is attached.The ActiveX control based on Document/view is introduced. A method of transforming an application program based on Document/view into an ActiveX control is presented, and developing software which can create a framework of ActiveX control based on Document/View is recommended.