Arcobjects-based Geographic Information System, Secondary Development And Realization

With the development of economy of Er Hai lake region, water quality of Er Hai lake is dropping and the ecological environment is being destroyed in recent years. For the sustainable development of the economy of the Er Hai lake region and environment protection and comprehensive administration of the basin, it is necessary to establish the Er Hai lake basin geographical information system (EHLBGIS). This is the breakthrough and studied meaning of this paper.Based on the digitization, informationization, scientific management of the whole Er Hai lake basin, the EHLBGIS system will offer the basic geographic information and powerful scientific decision to environmental protection, resources exploitation, lake science research, comprehensive administration. The EHLBGIS system can manage, operate, display the basic spatial geographic information data of the whole basin and supply spatial data to other relevant systems. The system can offer the decision support for management of the whole lake using relevant models to analyze at the same time.The paper discussed the development methods of GIS and pointed out the development approach which based on COM, OLE and ActiveX technology is the trend of secondary development of GIS. The paper discussed how to use the Object-Oriented technique to develop a gis system based on the ArcObjects, which were supported by the Environmental Systems Research Institute, Inc. The paper introduced the three methods of secondary software development based on ArcObjects and expatiated the properties, methods and events of the AO components in common use. Furthermore the paper described the establishment of the EHLBGIS system by using the C# visual programming language and the components of data processing, data editing and spatial analyzing. The use of AO can enhance the efficiency of application system development. Most users who need not to learn the complicated concept and operation of gis can use this system freely. The EHLBGSI system adopted the geodatabase spatial data model to organize and manage the spatial data. This data model can solute the storage and the relationship between the spatial data and the property data. It can solute the problems of mass data management, multi-format data accessing and multi-user data operation by using the Spatial Data Engine (SDE).The focus of this paper is to discuss the application gis development and implement based on AO. The paper took the EHLBGIS system for example to introduce the establishment process of system design, the general framework design, database design and function design, etc.