Research And Implementation Of Componnent WebGIS Based Upon RIA

RIA (Rich Internet Applications) is a new Web technology; it can bring the number of Internet users in the Rich experience. RIA has now become a hot spot in Web technology research field, and deeply influence s the Web applications. The Web technology for the current RIA provides shortcuts, it not only can provide good user experience, but also can make the program as easily as Web procedure deployment.WebGIS (Web Geographical Information System) is a kind of the geographic information system based upon the internet. The development of component technology to solve GIS function reuse provides a good solution. But, as the Web 2.0 ages, GIS application become more and more complicated, the pure component type WebGIS cannot satisfy the growing needs of users.Because of the poor expressive and bad interaction of component WebGIS,this paper propose component WebGIS based upon RIA, combined with the architecture of the WPF, Silverlight WCF technology, explored with good user experience Web front-end technology. And this paper also solves major problem in the WebGIS field. And then it introduced the RIA technology to Component WebGIS representation tier.The main work and achievements of this dissertation are listed as following:(1) Propose architecture of RIA and Component-based WebGIS.After analyzing the principles and basic characteristics of RIA and the key technology of Silverlight, on how to improve the client component WebGIS ability to interact, expressive and data, the paper gives an entire solution.(2) Design and implementation of WebGIS based on Silverlight presentation layer components. In this paper, we design and realize DeepEarth models, the key algorithms of WebGIS, the space projection system components, vector data structures, buffer analysis and other components.(3) A map of Silverlight-based slicing algorithm, described in detail Deepzoom algorithm, we share with the aggregation model of GIS services to represent geographic data as well as asynchronous communication technology by WPF and WCF technologies. The paper also constructs raster image cache implemented framework.(4) Construct WebGIS based on OpenLayers (Ajax) client, based on the OpenScales (Flex) client and based on Silverlight prototype system.thispaper draw a conclusion. This paper analye the performance of webGIS under different conditions.(5) Design and implementations of the "Geo-spatial database quality control System in Henan Province shared services" projects, which are this application of theory in practice, but also validate the RIA and the Component-based WebGIS the feasibility of the framework.