比如:ArcMap Expression(vbscript):
Function FindLabel ([ST_NAME], [SUFFIX])
IF ([SUFFIX] = "HWY") THEN
FindLabel = [ST_NAME]
END IF
End Function
在AE中,
//Global Variables
private IAnnotateLayerPropertiesCollection pAnnoProps;
private ILabelEngineLayerProperties pLabelEngine;
IBasicOverposterLayerProperties4 pBasic;
//Set on Layer Selection
pAnnoProps = pGeoLayer.AnnotationProperties;
//Label Creation Function
pBasic = new BasicOverposterLayerPropertiesClass();
pBasic.FeatureType = esriBasicOverposterFeatureType.esriOverposterPolyline;
pBasic.LineLabelPlacementPriorities = LinePlacement;
pBasic.LineLabelPosition = LinePosition;
pLabelEngine = new LabelEngineLayerPropertiesClass();
pLabelEngine.BasicOverposterLayerProperties = (IBasicOverposterLayerProperties) pBasic;
pLabelEngine.IsExpressionSimple = false;
IAnnotationExpressionEngine AnnExpEng = new AnnotationVBScriptEngineClass();
pLabelEngine.ExpressionParser = AnnExpEng;
pLabelEngine.Expression = "Function FindLabel (" + FieldLB.SelectedItem + ", " + FieldCB.Text + ") \n IF (" + FieldCB.Text + " " + EqualityBtn.Text + "\"" + CriteriaTxt.Text + "\") THEN \n FindLabel = " + FieldLB.SelectedItem + "\n END IF \n End Function"; pLabelEngine.Symbol = myTxtSym;
pAnnoLayerProps = (IAnnotateLayerProperties) pLabelEngine;
pAnnoLayerProps.Class = FieldLB.SelectedItem.ToString();
pAnnoProps.Add(pAnnoLayerProps);
可以看出表达式 只是把VBscript直接拿来变成字符串就可以使用,需要注意的是 需要回车以保持格式
来自:http://hi.baidu.com/xduoo/blog/item/13aa0636fc6450c7a2cc2bed.html