Research And Implementation Of WebGIS System Based On .Net Platform

With the rapid development of Internet and Geograhpic Information technology, people's requirement on Geography Information System(GI S)has become more and more demanding. As a conjunction of Internet technology and GIS technology, the development of WebGIS has closely related with the development of Computer technology.From 90s, as the network technology developed quickly which presented by Internet, WebGIS applications have deyelopmented rapidly.Meanwhile, there also appeared many questions WebGIS systems.Some of the questions are brought by Web software, such as the cross-platform and cross-language problems.Others are brought by GIS software, such as the data interoperative.So, we must do research in both GIS and Web areas to efficiently solve these problems.This thesis begins with the influences of Internet on GIS.It firstly introduces the conception and basic principle of Web-GIS.Then it focuses some advanced technologies in Web-GIS development such as JavaApplet,Servlet and JSP ect.It emphasis on introducing the structure of MapXtreme for c# platform.Then this text raised the model of WebGIS based on .Net framework of traditional three layers application structure model. The Air Denfence system was developed in Visual Studio .Net 2003,according to the diversity of users'platforms,demanding require ments of Concurrent Visiting,and high level of access traffic.This system adopts ASP.Net as client interface technology;Web Tier is constructed by IIS, and uses Oracle Spatial to ogranize and manage spatial data;. Then introduces common shortest route algorithm, analyzes in depth Dijkstra algorithrn.And it completes a WebGIS based on .NET and MapXtreme with Dijkstra algorithm.Finally, this thesis conclude the research and implementation of WebGIS system and then present the problems that need to be solved further and the vista of Web Service.