如何把Polygon用他上边的俩点切成俩段Polyline

如题

<P>第一步:将Polygon转为Polyline</P>
<P>Public Function PolygonToPolyline(ByRef pPolygon As IPolygon) As IGeometryCollection</P>
<P><BR>    Dim pGeometryCollectionPolygon   As IGeometryCollection<BR>    Dim pClone                       As IClone<BR>    Dim pSegmentCollectionPath       As ISegmentCollection<BR>Dim i                            As Long</P>
<P>    On Error GoTo ErrorHander<BR>    '创建一个新的Polyline geometry.<BR>    Set PolygonToPolyline = New Polyline<BR>    ' 克隆即将要操作的Polygon<BR>    Set pClone = pPolygon<BR>    Set pGeometryCollectionPolygon = pClone.Clone<BR>    '把Polygon的每个Ring创建为一个新的Path,并把Path增加到一个新的Polyline<BR>    For i = 0 To pGeometryCollectionPolygon.GeometryCount - 1<BR>        Set pSegmentCollectionPath = New Path<BR>        pSegmentCollectionPath.AddSegmentCollection pGeometryCollectionPolygon.Geometry(i)<BR>        PolygonToPolyline.AddGeometry pSegmentCollectionPath<BR>    Next i<BR>    Exit Function<BR>ErrorHander:<BR>     MsgBox Err.Description<BR>End Function</P>
<P>第二步：用polyline.SplitAtPoint方法分割这个polyline</P>

谢谢，解决了