arcgis engine C#中使用label

最新推荐文章于 2023-10-26 16:58:13 发布

最新推荐文章于 2023-10-26 16:58:13 发布 · 494 阅读

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#c# #操作系统

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本文介绍如何通过编程方式动态地更改地图上Label的表达式及应用Where子句来控制Label的显示条件，并提到了操作系统设置对于Label显示格式的影响。

1 动态更改label的expression


            IGeoFeatureLayer pGeoFeatureLayer = (IGeoFeatureLayer)axMapControl.get_Layer(1);

            IAnnotateLayerPropertiesCollection pAnnoLayerPropsColl = pGeoFeatureLayer.AnnotationProperties;

            IElementCollection ec;
            IAnnotateLayerProperties pAnnoLayerProps;
            pAnnoLayerPropsColl.QueryItem(0, out pAnnoLayerProps, out ec, out ec);


            ILabelEngineLayerProperties pLabelEngineLayerProps = (ILabelEngineLayerProperties)pAnnoLayerProps;
            pLabelEngineLayerProps.Expression = "bar";

            axMapControl.Refresh();

2 用where语句动态更改哪些要素类需要label


            IGeoFeatureLayer pGeoFeatureLayer = (IGeoFeatureLayer)axMapControl.get_Layer(1);
            IAnnotateLayerPropertiesCollection pAnnoLayerPropsCollection = pGeoFeatureLayer.AnnotationProperties;

			IAnnotateLayerProperties predictPointLabelEngineLayerProps;

            pAnnoLayerPropsCollection.QueryItem(0, out predictPointLabelEngineLayerProps, out ec, out ec);
            predictPointLabelEngineLayerProps.WhereClause = "id > 100";

3 label中绝对值小于1的小数不显示小数点前的0.
居然需要到操作系统的控制面板中修改

[img]http://dl2.iteye.com/upload/attachment/0105/3125/d7424f2b-1e39-3bc0-96d8-67e96fcddf56.jpg[/img]