Geographic Information Data Exchange

With the extensive applying of GIS,geography information industry has gotten swift and violent development in our country. As one of the means of getting spatial data, the exchange of spatial data has played a more and more important role on the modern construction of GIS.But,the applied range involves many subjects and many depts.,at the same time,during the developing GIS time, every department may use different means of data modeling basing on their special things,and use different GIS software from different manufacturers. In addition, every software has own spatical data format which results in the more difference on the structure of geography data. All of these has maken difficulty on the data exchange among systems built by different GIS software.Additionally, different departments have unlike understanding on the same geography phenomenon and different data definition. These made drawback of sharing and intercommunion of information in the cooperation of every depr and resulted that the rate of using spatical data was low and that gathering data repeatly and no compatibility usually happen. So it is imperious for the development of GIS to realize data coversion and sharing effectively.The paper will discusses the principle and methods of data comversion and explain advantage and disadvantage.Then,to the question of data exchange in KunMing gas item, lucubrate the MicroStation's DGN format and Maplnfo's MIF format.Using Delphi as development language and DLL of VC++,The data exchange fromDGN to M1F incompletely is realized by Delphi's program in which VC++ DLL is used too. (Here,we aim at the 2D graphics in MicroStat ion).By studying the task, I know more knowledge about the technology of geography information data exchange and correlative content especially, I know more about how to realize the exchange from DGN to MIF with progame.