如何限定entsel从AutoCAD选定的图元类型

南林浣风

假设用lisp编程时需要用entsel从AutoCAD界面选取一个矩形图元，请问怎样限制选取的图元对象只为矩形，而不能选定像圆或者多段线等其他类型的图元，谢谢指导。


该贴已经同步到 南林浣风的微博

llsheng_73

(defun isrectangle(e)
(if ...;;;自己写
    t nil)
)

(defun mysel()
  (while(not(isrectangle(car(setq en(entsel"选择矩形"))))))
en)

zzyong00

矩形不是cad内置对象，恐怕可能（不确定）不能直接用组码选，所以先按多线段过滤选择，然后再通过条件判定是不是矩形！

ZZXXQQ

(while (not (and (setq s1 (entsel "\n选择矩形: "))
(setq ent (entget(car s1)))
(wcmatch (cdr(assoc 0 ent)) "*POLYLINE")
(= (cdr(assoc 90 ent)) 4)
(progn
(setq ptlst (list))
(foreach x ent (if (= (car x) 10) (setq ptlst (cons (cdr x) ptlst))))
(equal (distance (car ptlst) (caddr ptlst)) (distance (cadr ptlst) (last ptlst)) 1e-6)
)
)))

Real_King

ZZXXQQ 发表于 2015-3-29 09:07
(while (not (and (setq s1 (entsel "\n选择矩形: "))
(setq ent (entget(car s1)))
(wcmatch (cdr(ass ...

精辟的代码

zjsru_18_505

ZZXXQQ 发表于 2015-3-29 09:07
(while (not (and (setq s1 (entsel "\n选择矩形: "))
(setq ent (entget(car s1)))
(wcmatch (cdr(ass ...

对角线互相平分且相等的四边形是矩形

sicky111

有意义吗  

南林浣风

ZZXXQQ 发表于 2015-3-29 09:07
(while (not (and (setq s1 (entsel "\n选择矩形: "))
(setq ent (entget(car s1)))
(wcmatch (cdr(ass ...

谢谢,非常感谢，但除了矩形，怎么限制其他类型的图元呢

自贡黄明儒

http://bbs.mjtd.com/forum.php?mo ... st%3D1%26digest%3D1