[求助]：帮我改进用NENTSEL空选时出错的问题？

nuance

下面的语句，若空选时，命令行提示出错，我想能在空选时推出即可，命令行不出现任何提示，象使用格式刷命令空选那样．但要保留现有功能，请指点．
(while (= nil (cdr (assoc 1 (entget (car (setq text1 (nentsel "\nselect source text (attrib,mtext):")))))))
   (princ "\nobject is not a text (attrib,mtext)!")
)

aidraft

(while (setq sel (nentsel "\nselect source text (attrib,mtext):"))
(if (= nil (setq TEXT1 (cdr (assoc 1 (entget (car sel))))))
    (princ "\nobject is not a text (attrib,mtext)!")))

LUCAS

2. 
   
3. (defun C:TT (/ FLAG TEXT1)
   
4.   (setq FLAG t)
   
5.   (while (and FLAG
   
6.               (setq TEXT1 (nentsel "\nSelect source text (attrib,mtext):"))
   
7.          )
   
8.     (if        (wcmatch (cdr (assoc 0 (entget (car TEXT1))))
   
9.                  "ATTRIB,MTEXT"
   
10.         )
    
11.       (progn
    
12.         (setq FLAG NIL)
    
13.         (alert "\n    GOOD!")
    
14.       )
    
15.       (alert "\nObject is not a text (attrib,mtext)!")
    
16.     )
    
17.   )
    
18.   (princ)
    
19. )
    

<br /> (defun C:TT (/ FLAG TEXT1)<br />   (setq FLAG t)<br />   (while (and FLAG<br />               (setq TEXT1 (nentsel "\nSelect source text (attrib,mtext):"))<br />          )<br />     (if        (wcmatch (cdr (assoc 0 (entget (car TEXT1))))<br />                  "ATTRIB,MTEXT"<br />         )<br />       (progn<br />         (setq FLAG NIL)<br />         (alert "\n    GOOD!")<br />       )<br />       (alert "\nObject is not a text (attrib,mtext)!")<br />     )<br />   )<br />   (princ)<br /> )<br />

梦断江南

[php]
(while
  (and (setq sel (nentsel "\nselect source text (attrib,mtext):"))
       (if (wcmatch (setq TEXT1 (cdr (assoc 0 (entget (car sel))))) "ATTRIB,MTEXT")
         nil
         (princ "\nObject is not a text (attrib,mtext)!")
       )
   )
)
[/php]