Engine中可否获取两条线段延长线上的交点？

IConstructMultipoint constructMultipoint = new MultipointClass();  

object param0;

object param1;

object isTangentPoint;  

constructMultipoint.ConstructIntersection(segment1, esriSegmentExtension.esriExtendTangents, segment2, esriSegmentExtension.esriExtendTangents, out param0, out param1, out isTangentPoint);

IMultipoint multipoint = constructMultipoint as IMultipoint;

IPointCollection pointCollection = multipoint as IPointCollection;

for (int i = 0; i < pointCollection.PointCount; i++)

{

    System.Windows.Forms.MessageBox.Show(Point :  + i +  X =  + pointCollection.get_Point(i).X +  Y =  + pointCollection.get_Point(i).Y);

}