请大家给看看

铆钉

(defun ok_VVV (/ HOLDANG ENAME VL-OBJ X P PX1 JANG) ;HOLDOSMODE)
(vl-load-com)
(setq HOLDORTH (getvar "orthomode"))
(setq HOLDANG (/ (* (getvar "snapang") 180) pi))
(setq ENAME (car (entsel "\n拾取天桥路线: "))
VL-OBJ (vlax-ename->vla-object;|将 AutoLISP 类型的对象名转换为 VLA 对象|; ENAME)
)
(setq zxzhs (getdist (vlax-curve-getstartpoint VL-OBJ) "\n点取天桥中心桩号："))
(setq cm (getvar "cmdecho"))
(setq os (getvar "osmode"))
(setvar "cmdecho" 0)
(setvar "osmode" 0)
(setq y (vlax-curve-getDistAtPoint VL-OBJ
(vlax-curve-getclosestpointto VL-OBJ
(vlax-curve-getpointatparam VL-OBJ
(vlax-curve-getparamatdist VL-OBJ zxzhs
;|(getdist (vlax-curve-getstartpoint VL-OBJ) "\n给定点："))|;
)))))
(setq yy (+ y 20))
(setq x (vlax-curve-getparamatpoint VL-OBJ;返回曲线在指定点的参数
(setq P (vlax-curve-getclosestpointto VL-OBJ;返回曲线上离指定点最近的点（在 WCS 上）
(vlax-curve-getpointatparam VL-OBJ;返回曲线上具有指定参数值的点
(vlax-curve-getparamatdist VL-OBJ yy;返回距曲线开始点为指定距离的曲线参数
))))))
(setq PX1 (vlax-curve-getfirstderiv;|返回曲线在指定位置的一阶导数（在 WCS 中）|; VL-OBJ X))
(setq JANG (angle '(0 0 0) PX1))
(command "_.snapang" (/ (* JANG 180) pi))
(setvar "orthomode" 1)
(command "_.line" P PAUSE "")
(setvar "orthomode" HOLDORTH)
(setvar "snapang" 0)
(setvar "osmode" os)
(setvar "cmdecho" cm)
(princ)
) 我要画的线长度是计算出来的 谁能帮我改改