Delphi版 ArcEngine 根据属性查询要素

function SearchByPropInfo(pLayer: ILayer; sWhere: string; out iCounts: Integer): IFeatureCursor;
var
   pQueryFilter: IQueryFilter;
   pFeatureLayer: IFeatureLayer;
   pFeatureSelection: IFeatureSelection;

   pSymbol  : ISymbol;
   pFillSymbol: ISimpleFillSymbol;
   pLineSymbol: ISimpleLineSymbol;
   pMarkerSymbol: ISimpleMarkerSymbol;

   pColor   : IRgbColor;
begin
   pFeatureLayer := pLayer as IFeatureLayer;

   pQueryFilter := CoQueryFilter.Create as IQueryFilter;
   pQueryFilter.WhereClause := sWhere;

   Result := pFeatureLayer.Search(pQueryFilter, False);

   pColor := CoRgbColor.Create as IRgbColor;
   pColor := getRGB(0, 255, 255, 255);
   //得到图层要素的几何类型
   case pFeatureLayer.FeatureClass.ShapeType of
      esriGeometryPoint, esriGeometryMultipoint:
         begin
            pMarkerSymbol := CoSimpleMarkerSymbol.Create as ISimpleMarkerSymbol;
            pMarkerSymbol.Color := pColor as IColor;
            pMarkerSymbol.Style := esriSMSCircle;

            pSymbol := pMarkerSymbol as ISymbol;
         end;
      esriGeometryPolygon:
         begin
            pFillSymbol := CoSimpleFillSymbol.Create as ISimpleFillSymbol;
            pFillSymbol.Color := pColor as IColor;
            pFillSymbol.Style := esriSFSDiagonalCross;

            pSymbol := pFillSymbol as ISymbol;
         end;
      esriGeometryPolyline:
         begin
            pLineSymbol := CoSimpleLineSymbol.Create as ISimpleLineSymbol;
            pLineSymbol.Color := pColor as IColor;
            pLineSymbol.Style := esriSLSSolid;
            pLineSymbol.Width := 2;
            pSymbol := pLineSymbol as ISymbol;
         end;
   end;

   pFeatureSelection := pLayer as IFeatureSelection;
   pFeatureSelection.SetSelectionSymbol := True;
   pFeatureSelection.SelectionSymbol := pSymbol;
   pFeatureSelection.SelectFeatures(pQueryFilter, esriSelectionResultNew, False);
   //得到被选的要素的个数
   iCounts := pFeatureSelection.SelectionSet.Count;
end;