Delete Layer(s)

[CADTutor]

Delete Layer(s)

Many new users of AutoCAD are surprised that it is not possible to erase a layer and all the objects on it using a single command - in fact I've often asked myself the same thing. Surely there ought to be a delete layer command. Well, load this lisp routine and you've got it.

This routine contains two commands:
del-layer simply removes any layer and all the objects on it that the user selects.
mdel-layer will do the same for multiple layers. Keep picking to add layers to a list and mdel-layer will delete them all in one go.

Both these commands are great timesavers and were donated by Mark Thomas - thanks Mark.



; Delete Layer(s)
; Written by Mark Thomas
; This file contains 2 functions:
; del-layer will delete all objects on a selected layer and purge it
; mdel-layer will delete all objects on selected layers and purge them

(defun c:del-layer (/ ent l_name ss cntr amt ssent)

;;;
;;; erases all objects on selected layer then purges that layer
;;;

(setvar 'clayer "0") ; set layer to 0

(if
; make sure we get something
(setq ent (car (entsel "\nSelect layer to remove: "))); test
(progn
; extract the layer name from the entity
(setq l_name (cdr (assoc 8 (entget ent))))

; create a selection set of all entites on layer 'l_name'
(setq ss (ssget "X" (list (cons 8 l_name)))
; set 'cntr' to number of items in selection set
cntr (1- (sslength ss))
amt (itoa cntr); make a string from an integer
)

(if
; does the sel set have anything in it
(> cntr 0); test

(while
; as long as 'cntr' is greater than or equal to 0
; keep looping
(>= cntr 0)

; extract the ename from the sel set
(setq ssent (ssname ss cntr))
(entdel ssent); delete that entity
(setq cntr (1- cntr)); subtract 1 from cntr
)

)
)
)
(command "_.purge" "LA" l_name "N")
(princ (strcat "\nErased " amt " items"))
(princ)
)

;;;
;;; erases all objects on selected layers and purges them
;;;

(defun c:mdel-layer (/ lst)
(setq cmd (getvar 'cmdecho))

; turn off the echo!
(setvar 'cmdecho 0)

(if
; make sure we get a list before we continue
(setq lst (fx-make-layer-list)); test

; now that we have a list run 'fx-rm-layer' on each of those items
(mapcar '(lambda (x) (fx-rm-layer x)) lst)
)

; reset the variable
(setvar 'cmdecho cmd)
(princ)
)

;;;
;;; functions ================================================== ====
;;;

(defun fx-rm-layer (l_name / ss sntr amt ssent)

;;;
;;; erase and purges all entites on 'l_name', a string
;;; returns the number of objects erased
;;;

(setvar 'clayer "0")

(if
; make sure the layer exists in the dwg
(tblsearch "layer" l_name); test
(progn ; continue
(setq ss (ssget "X" (list (cons 8 l_name)))
cntr (1- (sslength ss))
amt cntr
)

(if (> cntr 0)
(while
(>= cntr 0)
(setq ssent (ssname ss cntr))
(entdel ssent)
(setq cntr (1- cntr))
)
)
)
)
(if (> amt 0)
(command "_.purge" "LA" l_name "N")
)
; return the amount of entites erased
amt
)


(defun fx-make-layer-list (/ ent l_name entlst)

;;;
;;; generate a list of layer names based on user selection
;;; and returns that list
;;;

(while
; while user is selecting something continue loop
(setq ent (car (entsel "\nSelect Item on Layer: "))); test

; extract layer name from selected entity
(setq l_name (cdr (assoc 8 (entget ent))))
(prompt l_name); output the layer

(if
; make sure the layer isn't already in the list
(not (vl-position l_name entlst)); test

; if not then add it to the list
(setq entlst (cons l_name entlst))
)
)
)



Download del-layer.lsp (http://www.cadimage.net/cadtutor/lisp/files/del-layer.lsp) 3.44 KB

See the original topic (http://www.cadtutor.net/forum/viewtopic.php?t=2125) for more details.