problem with zoom

i have the code

(setq i 0) 
(repeat (sslength selpline)
     (setq pline_ent (ssname selpline i))            
     (setq lis_ent (entget pline_ent))
     (setq j 0)
     (setq b 0)
     (setq lis_coords '())   
     (repeat (length lis_ent)
           (if (= (car (nth j lis_ent)) 10)
               (setq lis_coords (append lis_coords (list (cdr (nth j lis_ent)))))
           )      
           (setq j (+ j 1))
      )
     (print "001")
     (setq selec (ssget "wp" lis_coords))
     (print "002")
     (repeat (sslength selec)    
     (print "003")
     (setq entblk (ssname selec b))   
     (print "004")
     (setq tipo_l (cdr(assoc 0 (entget entblk))))
     (print "005")

If i use zoom out the command is ok , run at (print 005)

BUT , if i use zoom in the command stop in "002"

Specify stretch point or [base point/Copy/Undo/eXit]:1 found

"001"

"002" ; error: bad argument type: lselsetp nil

And the error is in the line

(repeat (sslength selec)

And the message request Select Object is showed

Any Help ?

Hi Rodrigo, to use ssget with the graphic window selection modes (C, CP, F, W, WP) the specified area should be visible on the screen, so it would be wiser to use a zoom extents before. Or maybe if the drawing is too big you could do a zoom window to the extents of the selected polyline.

You could use in this case the boundingbox of that entity:

(vla-GetBoundingBox (vlax-ename->vla-object (car (entsel))) 'pmin 'pmax)
(vla-zoomwindow (vlax-get-acad-object) pmin pmax)

i have the code

 

(repeat (sslength [b]selpline[/b])
.....    

Are these irregular shape polylines?

Reinaldo, your tip helped me.

If the polyline is not showing the whole screen, it returns null.

Resolved using zoom

Thanks to all (reinaldo and pBe!)

You're welcome!