[LISP程序]：动态生成SOLID,哪位高人帮完善一下.

userzhluserzhl

(DEFUN c:aa ( / boolean code ent motion pt1 pt2 pt4 ptbase)
  (COMMAND ".UCS" "W")
  (setvar "osmode" 767)
(defun get_point( / ptbase)
(setq ptbase (GETCORNER PT1 "\n另一角点 :"))
)
(SETQ PT1 (GETPOINT "\n建柱子左下角点 :"))
(setq boolean t)
(while boolean
(setq motion (grread t 15 0))
(setq code (car motion))
(setq ptbase (cadr motion))
(cond
((= code 5)
(SETQ
        PT2 (LIST (CAR PT1) (CADR ptbase))
        PT4 (LIST (CAR ptbase) (CADR PT1))
  )
(setq ent (list (cons 0 "SOLID")
(cons 10 pt1) (cons 11 pt2) (cons 12 pt4) (cons 13 ptbase) (cons 62 256)
))
(entmake ent)
(entupd (entlast))
)
((= code 3)
(setq boolean nil)
)
((= code 11)
(entdel (cdr (assoc -1 ent)))
(setq boolean nil)
)
)
)
  (COMMAND ".UCS" "P")
  (PRINC)
)
;动态生成SOLID，如何让这个程在点取后才生成物体？并且为何捕捉会没了？