[CommandMethod("GTest")]
        public static void GTest()
        {
            var p1 = new Point3d(0, 0, 0);
            var p2 = new Point3d(100, 0, 0);
            var p3 = new Point3d(100, 100, 0);
            var p4 = new Point3d(0, 100, 0);

            var line = new Line(p1, p2);//创建直线
            var s1 = new Point3d(80, -40, 0);
            var s2 = new Point3d(20, 90, 0);
            var line2 = new Line(s1, s2);

            Point3dCollection pt3Coll = new Point3dCollection();//交点集合
            line2.IntersectWith(line, Intersect.ExtendBoth, pt3Coll, IntPtr.Zero, IntPtr.Zero);
            if (pt3Coll.Count > 0)//交点集合 2个交点
            {
                foreach (var jd in pt3Coll)
                {
                    var t = jd;
                }
            }

            pt3Coll = new Point3dCollection();//交点集合
            var circle = new Circle(new Point3d(50, 10, 0), new Vector3d(0, 0, 1), 50);//创建r=50的圆        
            circle.IntersectWith(line, Intersect.OnBothOperands, pt3Coll, IntPtr.Zero, IntPtr.Zero);
            if (pt3Coll.Count > 0)//交点集合 2个交点
            {
                foreach (var jd in pt3Coll)
                {
                    var t = jd;
                }
            }

            pt3Coll = new Point3dCollection();//交点集合
            var arc = new Arc(new Point3d(50, 10, 0), new Vector3d(0, 0, 1), 50, 0, 1.5 * Math.PI);//创建r=50,3/4的圆弧,    
            arc.IntersectWith(line, Intersect.OnBothOperands, pt3Coll, IntPtr.Zero, IntPtr.Zero);
            if (pt3Coll.Count > 0)//交点集合 1个交点
            {
                foreach (var jd in pt3Coll)
                {
                    var t = jd;
                }
            }

        }