List of Blocks & feed to dialog box

How to find out the list of existing blocks of the drawing and how to feed that list to the dialog box created by DCL:? please help me. I need the lisp code.

Use the tblnext function to iterate over the Block Table, or vlax-for if you wish to use Visual LISP to iterate over the Blocks Collection.

There are many examples to be found on the forum.

Search here for a lisp by AlanJT that creates the dialouge code and then like Lee Above would display answer will see if I can find.

here is code by AlanJT

(defun AT:ListSelect (title label height width multi lst / fn fo d item f)
 ;; List Select Dialog (Temp DCL list box selection, based on provided list)
 ;; title - list box title
 ;; label - label for list box
 ;; height - height of box
 ;; width - width of box
 ;; multi - selection method ["true": multiple, "false": single]
 ;; lst - list of strings to place in list box
 ;; Alan J. Thompson, 09.23.08 / 05.17.10 (rewrite)
 (setq fo (open (setq fn (vl-filename-mktemp "" "" ".dcl")) "w"))
 (foreach x (list (strcat "list_select : dialog { label = \"" title "\"; spacer;")
                  (strcat ": list_box { label = \"" label "\";" "key = \"lst\";")
                  (strcat "allow_accept = true; height = " (vl-princ-to-string height) ";")
                  (strcat "width = " (vl-princ-to-string width) ";")
                  (strcat "multiple_select = " multi "; } spacer; ok_cancel; }")
            )
   (write-line x fo)
 )
 (close fo)
 (new_dialog "list_select" (setq d (load_dialog fn)))
 (start_list "lst")
 (mapcar (function add_list) lst)
 (end_list)
 (setq item (set_tile "lst" "0"))
 (action_tile "lst" "(setq item $value)")
 (setq f (start_dialog))
 (unload_dialog d)
 (vl-file-delete fn)
 (if (= f 1)
   ((lambda (s / i s l)
      (while (setq i (vl-string-search " " s))
        (setq l (cons (nth (atoi (substr s 1 i)) lst) l))
        (setq s (substr s (+ 2 i)))
      )
      (reverse (cons (nth (atoi s) lst) l))
    )
     item
   )
 )
)

you need to create a list of block names here called LST then load above first

do block list here lst heres a start not tested 
(vl-load-com) 
 (setq adoc (vla-get-activedocument (vlax-get-acad-object))) 
 (vla-startundomark adoc) 
 (vlax-for i (vla-get-blocks adoc) 
 (setq lst (cons (cons (vla-get-name i) i) lst))
)


; here is calling section

(setq pickedblock (car (AT:ListSelect
   "Title "
   "label"
   10
   10
   "false"
   (vl-sort (mapcar (function car) lst) '<)
 )))

you need to create a list of block names here called LST then load above first

 

do block list here lst heres a start not tested 
(vl-load-com) 
 (setq adoc (vla-get-activedocument (vlax-get-acad-object))) 
 (vla-startundomark adoc) 
 (vlax-for i (vla-get-blocks adoc) 
 (setq lst (cons (cons (vla-get-name i) i) lst))
)


; here is calling section

(setq pickedblock (car (AT:ListSelect
   "Title "
   "label"
   10
   10
   "false"
   (vl-sort (mapcar (function car) lst) '<)
 )))

Such a function will create a list of the same and false (phantom) blocks with an asterisk (*) at the beginning of the name, I suspect the author of such unnecessary.

(setq pickedblock
      (car (AT:ListSelect
      "Title "
      "label"
      10
      10
      "false"
      (vl-sort
	[b](vl-remove-if-not
	  (function
	    (lambda (x) (/= (vl-string-elt (car x) 0) 42))
	  )
	  list
	)[/b]
	'<
      )
    )
      )
)

Thanks, Bigal's code is working.But the list is repeting the same block name several times.Can I stop it.

Are you running it more than once if so LST will grow you need to set lst back to nil each time or do at start.

Thanks again it works now nicely.