CAD二次开发学习笔记（C#.NET）之 获取与某曲线图元首尾相连接的所有曲线

当需要区别特定区域的图形时，有时需要识别与某曲线首尾相连的所有曲线，下属代码通过递归实现搜索，已进行封装

#region 获取与Curve相连的其它Curve-递归
        /// <summary>
        /// 获取与Curve相连的其它Curve-递归
        /// </summary>
        /// <param name="baseCurve"></param>
        /// <param name="curveDicAll"></param>
        /// <returns></returns>
        public static Dictionary<Curve, ObjectId> anotherCurveDicDiGui(this Curve baseCurve, Dictionary<Curve, ObjectId> curveDicAll)
        {
            Document doc = Application.DocumentManager.MdiActiveDocument;
            Editor ed = doc.Editor;

            //获取与曲线的起点相交的曲线图形
            Point3d pipeiDian = baseCurve.StartPoint;
            PromptSelectionResult res = ed.SelectCrossingWindow(pipeiDian, pipeiDian);
            List<Entity> entList = res.GetMulitEntityBySelect();

            //获取与曲线的终点相交的曲线图形
            pipeiDian = baseCurve.EndPoint;
            res = ed.SelectCrossingWindow(pipeiDian, pipeiDian);
            List<Entity> entList2 = res.GetMulitEntityBySelect();

            //把两个列表合并起来
            entList = entList.Concat(entList2).ToList<Entity>();

            Boolean isNew = false;
            foreach (Entity ent in entList)
            {
                if (curveDicAll.ContainsKey((Curve)ent) == false)
                {
                    isNew = true;
                }
            }

            //递归方法获取次级曲线
            if (isNew == true)
            {
                foreach (Entity ent in entList)
                {
                    if (curveDicAll.ContainsKey((Curve)ent) == false)
                    {
                        curveDicAll[ent as Curve] = ent.ObjectId;
                        return anotherCurveDicDiGui(ent as Curve, curveDicAll);
                    }
                }
                return null;
            }
            else
            {
                return curveDicAll;
            }

        }

        #endregion