下面这段函数主要是为了将Polygon分成多个三角形,这样进一步处理就能得到
这个Polygon里面的任意多个点(这些点一定落在这个Polygon里面)
public static IGeometryCollection GetTrianglesFromPolygon(IPolygon ipPg)
{
ILinePolygonHelper ipLPgHelper = new LinePolygonHelperClass();
IMultiPatch ipMultiPatch = new MultiPatchClass();
ipLPgHelper.Triangulate(ipPg, ref ipMultiPatch);
if (ipMultiPatch != null)
{
IGeometryCollection ipGeoColl = new GeometryBagClass();
IPointCollection ipPtColl = (IPointCollection)ipMultiPatch;
int nCount = ipPtColl.PointCount;
int nNum = nCount / 3;
object o = Type.Missing;
for (int i = 0; i < nNum; i++)
{
IPolygon ipPgTemp = new PolygonClass();
IPointCollection ipPgPtCol = (IPointCollection)ipPgTemp;
ipPgPtCol.AddPoint(ipPtColl.get_Point(i * 3), ref o, ref o);
ipPgPtCol.AddPoint(ipPtColl.get_Point(i * 3 + 1), ref o, ref o);
ipPgPtCol.AddPoint(ipPtColl.get_Point(i * 3 + 2), ref o, ref o);
//处理成简单多边形，使之符合ESRI 规范
ipPgTemp.SimplifyPreserveFromTo();
ipPgTemp.Close();
ipGeoColl.AddGeometry((IGeometry)ipPgTemp, ref o, ref o);
}
return ipGeoColl;
}
else
{
return null;
}
}
