ArcEngine 将圆形、矩形转换为多边形 ；ICircularArc、IEnvelope转化为IPolygon

多边形 ；ICircularArc、IEnvelope转化为IPolygon"/>

ArcEngine 将圆形、矩形转换为多边形 ；ICircularArc、IEnvelope转化为IPolygon

1、将ICircularArc转化为IPolygon

   1: ICircularArc pCircularArc = null;2: IRubberBand pRubberBand = new RubberCircleClass();3: pCircularArc = pRubberBand.TrackNew(axMapControl_Main.ActiveView.ScreenDisplay, null) as ICircularArc;4: if (pCircularArc == null)5:     return;6: object missing = Type.Missing;7: ISegmentCollection pSegmentColl = new RingClass();8: pSegmentColl.AddSegment((ISegment)pCircularArc, ref missing, ref missing);9: IRing pRing = (IRing)pSegmentColl;10: pRing.Close(); //得到闭合的环11: IGeometryCollection pGeometryCollection = new PolygonClass();12: pGeometryCollection.AddGeometry(pRing, ref missing, ref missing); //环转面13: IPolygon pPolygon = (IPolygon)pGeometryCollection;

2、将IEnvelope转化为IPolygon

   1: IEnvelope pEnvelope = null;2: IRubberBand pRubberBand = new RubberEnvelopeClass();3: pEnvelope = pRubberBand.TrackNew(axMapControl_Main.ActiveView.ScreenDisplay, null) as IEnvelope;4: if (pEnvelope == null)5:     return;           6: IPoint p1 = new PointClass();7: IPoint p2 = new PointClass();8: IPoint p3 = new PointClass();9: IPoint p4 = new PointClass();10: p1 = pEnvelope.UpperLeft;11: p2 = pEnvelope.LowerLeft;12: p3 = pEnvelope.LowerRight;13: p4 = pEnvelope.UpperRight;14: IPointCollection pPointCollection = new PolygonClass();15: object missing = Type.Missing;16: pPointCollection.AddPoint(p1, ref missing, ref missing);17: pPointCollection.AddPoint(p2, ref missing, ref missing);18: pPointCollection.AddPoint(p3, ref missing, ref missing);19: pPointCollection.AddPoint(p4, ref missing, ref missing);20: IPolygon pPolygon = (IPolygon)pPointCollection;

注意：在给IPointCollection添加点的时候要按照一定的顺序添加（按照顺时针或者逆时针的顺序选取起点进行添加，否则会使得图形发生变化）