求助:如何得出多义线直线两端点?

ymcui

(setq pt3 (osnap pt2 "midp"))这个是得出中点
如何得出多义线直线两端点?

2. (DEFUN C:tt()
   
3. (setq nm 0)
   
4.          (while   (setq test t)
   
5.            (while test
   
6.                   (setq ss (entsel "\n请点选矩形:"))
   
7.                   (setq test (not ss))
   
8.            )
   
9. (setvar "cmdecho" 0)
   
10. (command "LAYER" "S" (cdr (assoc 8 (entget (car ss)))) "" )
    
11. (setq obj (vlax-ename->vla-object (car ss)))
    
12. (setq PT2 (vlax-curve-getclosestpointto obj (cadr ss)))
    
13. (setq pt3 (osnap pt2 "midp"))
    
14. (vla-getboundingbox obj 'minpoint 'maxpoint )
    
15. (setq maxpoint (vlax-safearray->list maxpoint)
    
16. minpoint (vlax-safearray->list minpoint)
    
17. maxpoint (trans maxpoint 0 1)
    
18. minpoint (trans minpoint 0 1)
    
19. dx (/ (- (car maxpoint) (car minpoint)) 2.0)
    
20. dy (/ (- (cadr maxpoint) (cadr minpoint)) 2.0)
    
21. mpt1 (list (+ (car minpoint) dx) (+ (cadr minpoint) dy)))

(DEFUN C:tt()<br /> (setq nm 0)<br />          (while   (setq test t)<br />            (while test<br />                   (setq ss (entsel "\n请点选矩形:"))<br />                   (setq test (not ss))<br />            )<br /> (setvar "cmdecho" 0)<br /> (command "LAYER" "S" (cdr (assoc 8 (entget (car ss)))) "" )<br /> (setq obj (vlax-ename->vla-object (car ss)))<br /> (setq PT2 (vlax-curve-getclosestpointto obj (cadr ss)))<br /> (setq pt3 (osnap pt2 "midp"))<br /> (vla-getboundingbox obj 'minpoint 'maxpoint )<br /> (setq maxpoint (vlax-safearray->list maxpoint)<br /> minpoint (vlax-safearray->list minpoint)<br /> maxpoint (trans maxpoint 0 1)<br /> minpoint (trans minpoint 0 1)<br /> dx (/ (- (car maxpoint) (car minpoint)) 2.0)<br /> dy (/ (- (cadr maxpoint) (cadr minpoint)) 2.0)<br /> mpt1 (list (+ (car minpoint) dx) (+ (cadr minpoint) dy)))

Andyhon

(while (not (setq ss (entsel "\n请点选矩形:"))))
...

偏方:
(setq pta (osnap pt2 "end"))
(setq ptb (mapcar '+ pt3 (mapcar '- pt3 pta)))

请参考 vlax-curve-get*** 函数

liu_kunlun

(setq pra (vlax-curve-getParamatpoint e (vlax-curve-getClosestPointTo e (trans pt 1 0))))
(setq pt1 (trans (vlax-curve-getPointAtParam e (fix pra)) 0 1))
(setq pt2   (trans (vlax-curve-getPointAtParam e (1+ (fix pra))) 0 1))
pt,pt1,pt2均为UCS坐标

ymcui

谢谢,非常好.