THE IMPLEMENTATION OF UNIFORM SYMBOLIZATION BASED ON ARCGIS
Y L Liu, Z Q Ren, Y F Liu
Wuhan Uinv., School of Resource Environment Science, Wuhan, PRC.
The Implementation of Uniform Symbolization Based on ArcGIS
Liu yaoling1 Ren zhouqiao1,2 Liu yanfang1
(1. School of Resources and Environment Science, Wuhan University,129 Luoyu Road Wuhan,430079,China)
(2. Institute of Environment Resource , Soil and Fertilizer Science, Zhejiang Academy of Agricultural Sciences, 198 Shiqiao Road, Hangzhou 310021 , China)
Abstract: Symbol, Uniform Symbol, ArcGIS, Implementation
Symbol is map’s language, and symbolization of map is the primary tool for visualization of geographical information. Symbolization is one of most important research fields in GIS. There are many methods provided to different requirements about symbolization in the past researches, but it is seldom to integrate them together, where user not need to consider the object itself but to call a simple function to symbolization. It is transparent to the end user that how to select a suitable method, which make the user can easily to deal with it.
This paper mainly puts forward a method to realize the uniform and universal symbolization for user under the environment of ArcGIS application or custom systems developed with ArcObjects. And the purpose is to give a new symbolization scheme for developers with ArcGIS. In order to achieve this aim. In this paper we put forward three methods to three questions about the uniform symbolization. Firstly, different symbols can be done by one user’s interface, which means user can realize the symbolization of map only by calling one method. Here the map’s symbols are classified into common symbols and special symbols. The common symbols can be defined by certain rules, and the special symbols should be created dynamically according to the objects’ coordinate, where usually the width of symbol usually is related to the objects’ figure and range. To this, we put forwards a method by a custom Renderer. The key is implementation of the interface ‘IFeatureRenderer’ for the custom Renderer, where different arithmetic are set to different objects in the method ‘Draw’ of ‘IFeatureRenderer’. The second is automatically adjusting the symbol in map viewing, where constructing different symbol database for different scale is the base. By dynamically calculating the view’s scale of map window while refreshing view, whenever the scale is out of the range of current symbol database, the application do symbolization operation again by calling corresponding symbol database to realize multi symbol database to be used unaffectedly. The third is making a suite of symbolization module adaptable to many environment. Here, we implement the symbolization module just use the public primary component of ArcObjects, but avoid to use the special ‘Class Library’ to insure universality under the ArcGIS application or others developed with ArcObjects. In the end, we draw a conclusion that it is possible to realize uniform and universal symbolization based on ArcGIS.