Design And Technological Application Of Electronic Atlas Framework Based On Component-based Gis

With computer technology, information technology, GIS professional and technical development, Electronic map technology developed rapidly, and plays an more and more important role in the national economy and national defense construction. So far with the development of electronic maps, it develops fast in such as the visualization effects, software function, interface flexibility, dynamic integration and integration, ways of services, becoming more mature and perfect. But the prevalence problem of electronic atlas development is of a long production cycle, heavy workload of software programming, and poor reusability of software lead to duplication of work, to raise the issue of development costs. The development of electronic map GIS technology research increasingly become an important direction of development, specifically, how to fast, efficient, cheap and flexible development of e-map (set), is the key Atlas.In this paper, based on the study of the development of the performance of the current electronic atlas, structural model and development technology, I researched the current advantages and weaknesses of the development technology of electronic atlas, carry out a certain innovative development model of the Atlas framework.1. The design of electronic atlas framework independent on the dataWith components GIS program in combination of Object-oriented technology and component-based software technology, take ideas with the separation of data and software, I introduce the MapWinGIS.ocx components to develop electronic atlas framework. Based on MVC software design pattern, take full advantage of the multi-interface, easy to expand of component-based development, I research on the basic functions block of electronic atlas software, so the function modules and efficient migration and reorganization to get economic development model of the electronic atlas.2. More data format operation Expansion of GDAL/OGR class for raster, vector data read. to the characteristics of data format diversity requirements for digital map, I use GDAL data model and the abstract geometry model of OGR to read a greater variety of data formats, and provide interfaces to extended data types, provide a basis for follow-up development.3. The expansion of the MapWinGIS functionI investigate the component-based design and implementation of map symbols, designed interface for map symbols, as MapWinGIS provides a small number of symbols, especially the linear symbols, call system GDI (Graphics Device Interface) graphics device interface to finish drawing the symbols. in accordance with characteristics of point, line and surface symbols, design different rendering and coding method.Based on the above methods and techniques, I complete software framework for electronic atlas. Because the system characters in separation of model and data features, it can change according to data and atlas themes change, complete the reorganization, expansion and integration of the Atlas software. Through the example of electronic versions of western landscape mapping project, it proves the system development cycle with a short (3～4 months), with high software integration and high flexibility in the characteristics, and shorten the development of applications of the past. The system provides a common framework for the Atlas, based on the strategy of underlying structure and open source components to exploit the software; it achieves Atlas software with independent intellectual property rights in a short period of time. Electronic atlas integrated based on the framework of software can be used in the public version of the publication, in the western mapping project it has been a good application.Practice has proved that to develop electronic atlas software based on the component-based GIS, has perfect GIS functions, the software can be easily transferred and reused, with good scalability and new features such as style interface.