使用CurveCurve下的IntersectionsXY方法可以获得两条CurveVector的首尾交点。如果这两条CurveVector有两个以上的交点，那么就需要使用GetIntersectionPoints方法。

本文只显示如何通过IntersectionsXY方法来获取CurveVector的首尾交点：

为了方便观察交点，在求得交点后我们把起始点和结束点分别作为长度为0的Line并设置颜色和线宽添加到模型中。

        public static void CurveCurveTest()
        {
            DgnModel dgnModel = Session.Instance.GetActiveDgnModel();

            Element elem1 = dgnModel.FindElementById((ElementId)2074L);
            Element elem2 = dgnModel.FindElementById((ElementId)2075L);

            CurveVector cvElem1 = CurvePathQuery.ElementToCurveVector(elem1);
            CurveVector cvElem2 = CurvePathQuery.ElementToCurveVector(elem2);

            CurveVector cv1 = CurveVector.Create(CurveVector.BoundaryType.Open);
            CurveVector cv2 = CurveVector.Create(CurveVector.BoundaryType.Open);

            CurveCurve.IntersectionsXY(cv1, cv2, cvElem1, cvElem2);
            cv1.GetStartEnd(out DPoint3d pA, out DPoint3d pB);

            DSegment3d segment1 = new DSegment3d(pA, pA);
            LineElement lineElem1 = new LineElement(dgnModel, null, segment1);

            ElementPropertiesSetter setter = new ElementPropertiesSetter();
            setter.SetColor(2);
            setter.SetWeight(10);
            setter.Apply(lineElem1);
            lineElem1.AddToModel();

            DSegment3d segment2 = new DSegment3d(pB, pB);
            LineElement lineElem2 = new LineElement(dgnModel, null, segment2);
            setter.Apply(lineElem2);
            lineElem2.AddToModel();

        }