The Design And Realization Of The System Of Map Symbol Making In ComGIS

As an effective tool to obtain, manage, operate and display geographic information, GIS is applied more and more widely day after day. Neither can traditional GIS software meet the demands of the application, nor conform to the mainstream of software technology in deep extent. These problems listed above must be solved by a new software technology implemented to develop GIS, Components GIS, briefly called ComGIS, is a new generation of GIS based on Components Software and Component-Based Development technologies, which meets with the requirement of providing new idea to solve the problems the traditional GIS faces completely.The system of map symbol making is one of the indispensable basal functions in GIS. In Traditional GIS software, there is devoid of the function making the system of map symbol. So it is necessary to build a common system of making map symbol based on component technology.This paper introduces the principles and features of component technology, the advantage of component GIS, and designs the component framework, component interfaces and component classes based on the COM technology. In the system, the interface is designed to manage the outer programming symbol. Finally, the strategy that the symbol system integrated with MapObjects is put forward and three custom symbols of MapObjects are realized.The system test proves that the design of the map symbol system is reasonable and the map symbol system has good opening.