If you’re like me, you have a handful of routines, scripts or macros that let you basically “turn on” layers
Thaw those frozen layers; Unlock those locked layers; Turn on those Off layers…
The routine featured today combines all of those functions into one dialog box. The great thing about this routine is that it shows you only those layers that are currently Off, Frozen or Locked so that you don’t have the other layers that are turned on cluttering up your view. There is an optional function that lets you control these same layer states if they exist in an XREF. Simply check the box next to “Xrefs layers” for the ability to control these layers as well.

Here’s how:

• Layer_On <enter> to start
• Check the boxes under the “Properties” section that you would like to be turned “On”
• Check the box next to “Xrefs Layers” to gain control over those layers as well

Select the layers under the “Layer List” section that you want to be turned “ON”. If all layers are needed to be selected, click the “Select all” button.

This routine was provided by Stefan M. at the Autodesk forums. Please refer questions about the routine there: http://forums.autodesk.com/t5/Visual-LISP-AutoLISP-and-General/Thaw-layers-from-custom-dialogue-box/td-p/3944033/page/2

 ; Turn ON selected layers
 ; Stefan M. - 05.06.2013
 ; http://forums.autodesk.com/t5/Visual-LISP-AutoLISP-and-General/Thaw-layers-from-custom-dialogue-box/td-p/3944033/page/2
(defun C:LAYER_ON (/ *error* acDoc filen filew id l layers r prop var labels keys final l_name selected_layers)
  (vl-load-com)
  (setq acDoc (vla-get-activedocument (vlax-get-acad-object)))
  (vla-startundomark acDoc)

  (defun *error* (m)
    (and
      m
      (not (wcmatch (strcase m) "*CANCEL*,*QUIT*"))
      (princ (strcat "\nError: " m))
      )
    (vla-endundomark acDoc)
    )

  (defun remove_duplicates (lst)
    (if lst
      (if (vl-position (car lst) (cdr lst))
        (cons (car lst) (remove_duplicates (vl-remove (car lst) (cdr lst))))
        (cons (car lst) (remove_duplicates (cdr lst)))
        )
      )
    )

  (defun prompt_list ()
    (setq final (remove_duplicates (apply 'append (mapcar '(lambda (a b) (if (eq "1" a) b)) var l))))
    (if (eq "0" (last var))
      (setq final (vl-remove-if '(lambda (a) (wcmatch a "*|*")) final))
      )
    (if final (setq final (acad_strlsort final)))
    (start_list "a_list")
    (mapcar 'add_list final)
    (end_list)
    )

  (setq prop   '((LayerOn . 0) (Freeze . -1) (Lock . -1) (Plottable . 0))
        labels '("OFF Layers" "Frozen Layers" "Locked Layers" "UnPlottable Layers" "Xrefs Layers")
        keys   '("tog1" "tog2" "tog3" "tog4" "tog5")
        l      '(nil nil nil nil)
        )

  (vlax-for la (setq layers (vla-get-layers acDoc))
    (setq l (mapcar
              '(lambda (a b)
                 (if (= (vlax-get la (car a)) (cdr a))
                   (cons (vla-get-Name la) b)
                   b
                   )
                 )
              prop
              l
              )
          )
    )
  (setq l (reverse (cons (vl-remove-if '(lambda (a) (eq (strcase a) "DEFPOINTS")) (last l))
                         (cdr (reverse l))
                         )
                   )
        )

  (if (vl-some 'vl-consp l)
    (progn
      (setq filew (open (setq filen (strcat (getvar 'dwgprefix) "temp_layer_dialog.dcl")) "w"))
      (write-line
        "layer_on_dialog : dialog { label = \"SELECT LAYERS\";
       : row {
       : list_box { label = \"Layer List\"; key = \"a_list\"; width = 30; height = 15; multiple_select = true; allow_accept = true;}
       : column {
       : boxed_column { label = \"Properties\"; fixed_height = true;  alignment = top;"
        filew
        )
      (mapcar
        '(lambda (a b c)
           (if c
             (write-line (strcat "       : toggle { label = \"" a "\";    key = \"" b "\"; }") filew)
             )
           )
        labels keys (append l '(T))
        )
      (write-line "       }: button { label = \"Select all\"; key = \"selall\"; alignment = bottom;}
       }}ok_cancel;}" filew)
      (close filew)

      (if
        (>= (setq id (load_dialog filen)) 0)
         (if
           (new_dialog "layer_on_dialog" id)
            (progn
              (setq var (subst "0" nil (read (cond ((getenv "layer_dialog_box_settings")) ("(\"1\" \"0\" \"0\" \"0\" \"0\")")))))
              (prompt_list)
              (action_tile "a_list" "(setq selected_layers $value)")
              (action_tile "selall" "(set_tile \"a_list\" (setq selected_layers (apply 'strcat (mapcar '(lambda (a) (strcat (itoa (vl-position a final)) \" \")) final))))")
              (mapcar
                '(lambda (a b)
                   (if b
                     (progn
                       (action_tile
                         a
                         "(setq var (mapcar 'get_tile keys) selected_layers nil) (set_tile \"a_list\" \"\") (prompt_list)"
                         )
                       (set_tile a (nth (vl-position a keys) var))
                       )
                     )
                   nil
                   )
                keys
                (append l '(T))
                )
              (setq r (start_dialog))
              (unload_dialog id)
              (if var
                (setenv "layer_dialog_box_settings" (vl-prin1-to-string var))
                )
              )
            (princ "\nWrong dialog definition")
            )
         (princ "\nDCL file not found")
         )
      (if (findfile filen) (vl-file-delete filen))
      (if
        (and (= r 1) selected_layers)
        (progn
          (foreach x (read (strcat "(" selected_layers ")"))
            (mapcar
              (function
                (lambda (a b c)
                  (if
                    (and
                      (eq "1" c)
                      (vl-position (setq l_name (nth x final)) a)
                      )
                    (vlax-put (vla-item layers l_name) (car b) (- (1+ (cdr b))))
                    )
                  )
                )
              l
              prop
              var
              )
            )
          (if
            (or
              (eq (nth 1 var) "1")
              (eq (nth 2 var) "1")
            )
            (vla-regen acDoc acActiveViewport)
          )
        )
      )
    )
    (princ "\nAll layers are on and plottable.")
    )
  (*error* nil)
  (princ)
  )