转自原文

 

有时候，我们要对图层上的地物进行有选择性的显示，以此来满足实际的功能要求。

按下面介绍的方法可轻松实现图层属性过滤显示：

  1、当图层已经加载时

private void ShowByFilter(AxMapControl sMapCtr, IFeatureLayer sFlyr, string sFilter)        {            ESRI.ArcGIS.Carto.IFeatureLayerDefinition pDef = (ESRI.ArcGIS.Carto.IFeatureLayerDefinition)sFlyr; pDef.DefinitionExpression = sFilter; sMapCtr.ActiveView.Refresh(); }

2、当图层尚未加载时

private IFeatureClass GetFeatureClass(IWorkspace pWS, string sTabName, string sAttrFilter)        {            try { if (pWS == null || sTabName == null) return null; IFeatureWorkspace pFWS = pWS as IFeatureWorkspace; IFeatureClass pFC = null; pFC = pFWS.OpenFeatureClass(sTabName); IQueryDef pQueryDef = pFWS.CreateQueryDef(); pQueryDef.Tables = sTabName; pQueryDef.WhereClause = sAttrFilter; IQueryName2 pQueryName = new FeatureQueryNameClass(); pQueryName.PrimaryKey = pFC.OIDFieldName; pQueryName.QueryDef = pQueryDef; IDataset pDS = (IDataset)pFWS; IWorkspaceName pWSName = (IWorkspaceName)pDS.FullName; IDatasetName pDSName = (IDatasetName)pQueryName; pDSName.WorkspaceName = pWSName; IName pName = (IName)pQueryName; pFC = pName.Open() as IFeatureClass; return pFC; } catch { return null; } }