Design And Implementation Of WebGIS Client Platform Based On Flex

WebGIS is a product combined with technologies of GIS and Internet. With the development of Internet, WebGIS is becoming more and more popular and a necessary tool for daily life. Conventional WebGIS client platform relies on Html and has drawbacks of poor interaction with users, weak capability of calculation and insufficient sustainability of GIS functions. The appearance of RIA technology brings a new chance for WebGIS. Flex is one of the leading RIA technologies right now, this paper developed WebGIS client platform with Flex technology, and the SOG server of Zhejiang University Intelligent Lab is used as server for the current platform.Current leading WebGIS provides interfaces by class and package, which requires sophisticated second developers and long time for developing. This WebGIS platform offers simple and easily understood interfaces based on functional types, thus greatly decreased the difficulty for the second developer and make the fast developing WebGIS application system come true.Considering the low efficiency of the label display, this client platform improved the standard label controling method, the improved method increased 12-18 times. With requirements of variable points during application, this platform supports circle points and point pictures, and point pictures can freely rote and orientate. To improve the efficiency, this platform created memory layers and makes uniform management for the memory layers and persistant layers.With requirements of too much geographical data transfering, this platform uses the binary system to transfer data based on analysis of the interaction between Flex and the server.This client platform shows great practicability by successfully supporting Impression of Chongqing and Tide Forecasts Show Platform of Zhejiang.