Research And Implementation Of .NET-Based WebGIS System

With the rapid development of Internet technology, people's requirement on Geography Information System (GIS) has become more and more demanding. It has become the direction of GIS development to exploit the advantages of Internet to promulgate geography data on web, provide users with access, browse, and analysis to geography information. Thus, the Internet-based geography information system, WebGIS, comes out.Although WebGIS has been widely used in different trades, the application of this technology still confronts many theoretical and technical problems: For example, the gap between the concurrent visiting capability and ceaseless extension of the system scope; lack of the compatibility for different operation systems; difficulties in system development, implementation and maintenance; inappropriateness of data sharing and data structure and lack of effective format for service presence. Driven by these problems and based on deep analysis of traditional WebGIS, this study chooses Mircosoft.NET as the development platform to design and realize a component-based distributed GIS infrastructure following relevant OpenGIS design standards. In this study, the technology solution on both server-side and client-side is proposed for the infrastructure.In order to reduce the traffic pressure on servers and optimize system resources, this article studies two important COM+ technologies——pool and Load-balance, proposes the Optimal COM+ pool threshold algorithms as well as self definition Load-balance algorithm, and deduces the relevant formulas. Also in order to improve the performance of webpage presence and implementation capacity and effectively avoid WebGIS security risks, this paper intensively studies the technologies of ASP.NET and .net identification, proposes a solution of the self-identification security authorization. On Client-side, the author suggests that the system should use SOAP to enhance the heterogeneous capacity of the system, use XML to realize picture hierarchy, which would effectively improve system performance and cross-platform capabilities; and the use of customer-data...