Research On Large-scale Cartographic Technology Based On AutoCAD VBA

In response to the national economic construction and the social development of the growing,which demand for large quantities of large scale topographic map,this paper analyse the new characteristics of the large scale topographic map mapping method which under the current technical conditions,and sum up the problems of AutoCAD in large scale topographic map mapping,expounds the basic concept of the further developing platform based on AutoCAD. On this basis,this paper carry out the programing for symbols of large scale topographic map based on AutoCAD、 the mapping process of the database in AutoCAD expression、the rapid customize operation interface、researching the use of database management and maintenance of large scale topographic map symbol database technology.The results including AutoCAD Easy Mapping toolbox,AutoCAD mapping tool self-customized solutions and AutoCAD large scale topographic map symbolization scheme.The results reduces duplication of work significantly,pulls down the threshold of the mapping tools customize,improves the flexibility when AutoCAD handle various forms of the original data and the applicability of the results of application when facing the diversified results. The main contents as follows:(1)Lighting AutoCAD mapping procedures to database,it will achieve a rapid selfcustomized toolbox and mapping parameters,pull down the threshold of the mapping tools customize,make up the insufficient of the general mapping software’s pertinence,which can convert the individual and occurrence problem on perticular mapping work.(2)The toolbox based on Loosely Coupled Systems thought of software engineering,it has a well repeated use,compatible with the commonly used plug-in units of AutoCAD fully;The design of the scheme on large scale topographic map symbolization separated from the code,it can meet the diverse needs of flexible task;The symbol graphics drawed is not dependent on the further development environment,and the result can carry out the varied application.(3)The concept and method of "sub elements", "block filling" are introduced during the process of rendering the AutoCAD topographic map symbols. The problem of drawing procedures in the AutoCAD part of the complex symbols are sloved,the tool Fast symbolize designed can easy complete the complex symbolic operation in AutoCAD.(4)The medthod designed of AutoCAD topographic map virtual framing,which meet the needs of production framing,and it will not destroy the integrity of the whole map data,facilitate analysis and use of the data,save the workload of check and modifications for map and revising the connect boundary at the same time,also,ensure the edge quality.