[编程交流] 圆部分长度

(defun ArcLen (Ent pt1 pt2)
 (abs
   (- (vlax-curve-getDistatPoint Ent Pt2)
        (vlax-curve-getDistatPoint Ent Pt1))))

(defun c:test (/ Cir p1 p2)
 (if (and (setq Cir (car (entsel "\nSelect Circle: ")))
          (setq p1 (getpoint "\nSelect First Point: "))
          (setq p2 (getpoint "\nSelect Second Point: ")))
[color=Red][b]    (ArcLen Cir p1 p2)))[/b][/color]

(defun arclen (ent pt1 pt2)
 (if (not (vl-catch-all-error-p (vl-catch-all-apply 'vlax-curve-getendparam (list ent))))
   (abs (- (vlax-curve-getdistatpoint ent (vlax-curve-getclosestpointto ent pt2))
       (vlax-curve-getdistatpoint ent (vlax-curve-getclosestpointto ent pt1))
    )
   )
 )
)
(arclen (car (entsel)) (getpoint) (getpoint))

(defun ArcLen (Ent pt1 pt2 / Cir Arc)
 (vl-load-com)
 (if (not (vl-catch-all-error-p
            (setq Cir
              (vl-catch-all-apply
                'vla-get-Circumference
                  (list
                    (vlax-ename->vla-object Ent))))))
   (list
     (setq arc
       (abs
         (- (vlax-curve-getDistatPoint Ent
              (vlax-curve-getClosestPointto Ent Pt2))
            (vlax-curve-getDistatPoint Ent
              (vlax-curve-getClosestPointto Ent Pt1)))))
     (- Cir arc))))
(defun c:test (/ ent p1 p2)
 (if (and (setq ent (car (entsel "\nSelect Circle: ")))
          (setq p1 (getpoint "\nPt1: "))
          (setq p2 (getpoint "\nPt2: ")))
   (print (ArcLen ent p1 p2)))
 (princ))