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

null;

new RubberCircleClass();

as ICircularArc;

null)

return;

object missing = Type.Missing;

new RingClass();

ref missing);

   9: IRing pRing = (IRing)pSegmentColl;

//得到闭合的环

new PolygonClass();

//环转面

  13: IPolygon pPolygon = (IPolygon)pGeometryCollection;

2、将IEnvelope转化为IPolygon

null;

new RubberEnvelopeClass();

as IEnvelope;

null)

return;           

new PointClass();

new PointClass();

new PointClass();

new PointClass();

  10: p1 = pEnvelope.UpperLeft;

  11: p2 = pEnvelope.LowerLeft;

  12: p3 = pEnvelope.LowerRight;

  13: p4 = pEnvelope.UpperRight;

new PolygonClass();

object missing = Type.Missing;

ref missing);

ref missing);

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）