private IGeometry GetGeo(IFeatureLayer pFlyr)
{
IEnumGeometry pGeos = new EnumFeatureGeometryClass();
IEnumGeometryBind pGeosBind = pGeos as IEnumGeometryBind;
IFeatureSelection pflyrSelection = pFlyr as IFeatureSelection;
pflyrSelection.SelectFeatures(null, esriSelectionResultEnum.esriSelectionResultNew, false); pGeosBind.BindGeometrySource(null, pflyrSelection.SelectionSet);
pGeos.Reset();
IPolygon sPoly = new PolygonClass();
ITopologicalOperator pTopo = sPoly as ITopologicalOperator;
pTopo.ConstructUnion(pGeos);
pTopo.Simplify();
sPoly = pTopo as IPolygon;
pflyrSelection.Clear();
return sPoly;
}
执行上面的代码段可以把图层上的所有实体合并。注意红色部分的那行代码，不写此行代码，pGeos 里的图形个数为0，最后得到的spoly是空。