ArcEngine二次开发之提取外包矩

最近做项目用到一些AE的知识，记录一下。

1、通过ITopologicalOperator接口，此方法适用于需要获得包含几个或多个要素的最小外包矩形

        public IEnvelope GetEnvelope(IGeometryCollection pGeometryCollection)

        {           

            IPolygon pPolygon = new PolygonClass();

            ITopologicalOperator pTopo;

            pTopo = pPolygon as ITopologicalOperator;

            pTopo.ConstructUnion(pGeometryCollection as IEnumGeometry);

            IEnvelope pEnvelope = pPolygon.Envelope;

            return pEnvelope;

        }

2、通过IGeoDataset 接口，此方法适用于获得一个要素图层的外包矩形（即包含所有要素的最小外包矩形）

        public IEnvelope GetEnvelope(IFeatureClass pFeatureClass)

        {            

            IGeoDataset pGeoDataset;

            pGeoDataset = pFeatureClass as IGeoDataset;

            IEnvelope pEnvelope = pGeoDataset.Extent;

            return pEnvelope;

        }

3、要素的属性 pFeature.Extent，获得单个要素的外包矩

        public IEnvelope GetEnvelope(IFeature pFeature)

        {

            IEnvelope pEnvelope = pFeature.Extent;

            return pEnvelope;

        }