可编辑复杂线状符号库的设计与实现

针埘GDI＋绘制复杂线状符号存在符号不可编辑与遮捎等问题，设计了一种可编辑的复杂线状符号的组织方法，该方法将复杂线状符号分解为实线、虚线和点线蔓种基本单元，进而设计了基于这一种基本单元的复杂线状符号参数描述方法，解决了GDI＋绘制复杂线状符号存在符号不可编辑与遮挡等问题。采用C#实现了可编辑线状符弓库的设计与开发．建立了1：10000地形图符号库。最后，对本文方法与GDI＋方法的绘制效率进行了比较试验。试验表明本文方法不仅解决了GDI＋绘制复杂线状符号存在符号不可编辑与遮挡等问题．并且绘制效率也明显优于GDI＋方法．

The Design and Implementation of Modifiable Complex Linear Symbol Base

Cartographic symbol base is a very important component of GIS. Now in many GIS systems, thc symbol base is implemented based on GDI＋. However, the symbols drawn by GDI＋ can not be modified locally, and some symbols usually cover the symbols at the lower level. In order lo solve these prot）lems, an organization method for line symbols was designed. The complicated linear symbol is divided into three units, i.e., point line, dash line and soTid line. Aspecial data strueture for Ihe organization of tile complicated linear symbols is designed based on the lhree units. Based oil the methods present in this paper, a 1：10000 Topographic linear symbol base is implemented. The experiment used to compare Ihe efficiency of the method present in this paper and GDI＋ is done. The experiment shows that the method presented in this paper not only solved the problems with GDI＋, tile efficiency of drawing the complex linear symbols also has been improved. This method has been successfully used in the eVillage change-only information colleetion system.