Check The Type Of Entity

[harilalmn]

Hello All,

I am just learning AutoLisp. So I know a little about it.

 

I thought of writing a program to draw a line from the intersection (if not intersecting, when they are extended) of two lines.

 

Thought of using Inters Function and it worked fine. But now I want to check if the selected entity is a line.

How to do that?

I wrote something like this but it fails;

 

(defun c:Intr()
   (Setq Line1 (car (entsel "\nSelect First Line:")))
   (CheckObject Line1)

   BLAH BLAH BLAH.....


)

(defun CheckObject(Enty)
 (Setq ObjType(assoc 0 (entget (Enty))))
 (if
   (/= ObjType "LINE")
   (
   (alert "No Lines Selected... Ending")
     (exit)
   )
 )
)

 

Please help...

[BIGAL]

You also need to check if its a polyline and maybe explode it so you can still inters it.

 

Will post at work tomorrow code for this.

[Tharwat]

Check this out ......

 

(Setq Line1 (car (entsel "\nSelect First Line:")))
(if (eq (cdr(assoc 0 (entget Line1)))"LINE")
 (alert "That's Right")
 (alert "I am sorry, That's wrong")
 )

 

Tharwat

[harilalmn]

Wow... That Worked... Thats what I wanted.

Could you please tell me where I went wrong in my code above?

 

Also, If the user is not selecting a line, how can i repeat the step till he selects a line?

[MSasu]

The ENTGET will return a list of dotted pairs; to get the type of entity use only the second item - in your excerpt code you are trying to compare a list (dotted pair) with a string; also the entity name shouldn't be enclosed in parenthesis. Please find below your corrected code:

 

(defun CheckObject(Enty)
 (Setq ObjType [color=red](cdr[/color] (assoc 0 (entget Enty))[color=red])[/color])[color=red] ;(Enty)))))[/color]
 (if
   (/= ObjType "LINE")
   (
   (alert "No Lines Selected... Ending")
     (exit)
   )
 )
)

 

Regards,

Mircea

[harilalmn]

Oh.... I got it.. Thanks a lot...!!!

[Tharwat]

This one to force the user to select only a line ....

 

(while
   (not
       (and (Setq Line1 (car (entsel "\nSelect First Line:")))
            (eq (cdr (assoc 0 (entget Line1)))"LINE")
      ))
 (prompt "\n Please select Line onle !!!")
 )

[harilalmn]

Thanks tharwat313....

Hmm... This is why I like this forum the most... Someone helps me out in no time, always.

[Tharwat]

Thanks tharwat313....

Hmm... This is why I like this forum the most... Someone helps me out in no time, always.

 

You're welcome any time.

 

Regards,

 

Tharwat