基于GDI+处理注记与同色符号压盖关系的方法

薛智勇，汶建龙

(西安测绘总站，陕西 西安 710054)

摘要：传统条件下处理注记与同色符号压盖关系的方法，通常会存在增加数据量、破坏被压盖符号的数据完整性以及操作不灵活等问题。针对这种现象，提出基于GDI+裁剪技术处理注记与同色符号压盖关系的方法。通过计算获取到注记压盖范围内同色符号占据的绘图区域，当绘制被压盖同色符号时，利用GDI+裁剪特性来限制该符号在上述区域内的图形绘制，从而达到“裁剪”注记压盖区域内同色符号的目的。文中方法的整个处理过程完全不需要人工干预就能自动完成，且能够突破过去流水线式的生产作业模式，随机选择不同阶段的编辑内容进行处理，在很大程度上提高了注记与同色符号压盖关系处理的质量和效率。

关键词：GDI+;注记;裁剪;压盖关系;分色版

中图分类号：P282

收稿日期：2014-07-15

作者简介：薛智勇(1969-)，男，高级工程师.

A method of processing the overlapping relations between annotation texts and the same color symbols based on GDI+

XUE Zhi-yong,WEN Jian-long

(Xi’an Information Technique Institute of Surveying and Mapping,Xi’an 710054,China)

Abstract：The traditional methods-processing the overlapping relations between annotation texts and the same color symbols may have some problems such as increasing the amount of data,destroying the integrity of feature symbol data and inflexibility of operations.So the method of processing the overlapping relations between annotation texts and the same color symbols based on GDI+ clip technique is proposed.In order to achieve the purpose of trimming the symbols that have the same color as annotation text’s under annotation text，it can get the drawing area of the symbols that have the same color as annotation text’s under annotation text，and limit the graphics drawing under the annotation text using GDI+ clip characteristics while drawing the same color symbols.This method needs no manual intervention and can be accomplished automatically,which will break the past pipelining production mode，randomly choose the edit contents of some different phases to treat，and greatly improve the quality and efficiency.

Key words：GDI+；annotation；clip；overlapping relation；process plates

地图表达内容丰富，即使注记配置工作做得再完美，也避免不了注记压盖其他同色符号的现象。针对这种问题，传统的处理方法有蒙片法或者切割法[1]。但是蒙片法不仅会增加数据量，还会影响到地图要素的管理模式。例如，通过蒙片法处理后的地图内容，蒙片符号和注记内容往往是分离的，蒙片符号通常会被放在单独一层，与注记层没有任何联系，这就无法实现对某一注记与其对应蒙片同时管理的功能(如同时显示或隐藏等)。通过切割法处理后的地图内容，被切割线划所在的符号结构又会遭到破坏，使得被切割符号在GIS应用中无法再单独进行可视化表达。……