[编程交流] 选择lisp

;;*****************************************************************************
;                     LASTN.LSP V1.0 by Zoltan Toth
;    ZOTO Technologies,
;    23 Greenhills Dve,
;    Melton, 3337.
;    E-MAIL: zoltan.toth@ains.net.au
;       WWW: http://www.ains.net.au/zoto/
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; This program will select the last n objects created in a drawing where n
; is an integer input by the user. This is most useful when you create a
; number of objects with the COPY, MIRROR or ARRAY commands and you wish to
; work with the ones just created. LASTN has been written so that it can be
; used in three different ways for maximum flexibility. First, it can be
; called by itself at the "Command:" prompt and the objects so selected can
; be accessed by a later command with the "Previous" option. Second, it can
; be called transparently (with a preceding apostrophe) at a "Select
; objects:" prompt and the objects selected will be passed back to the
; waiting command. Since it can be tedious to type in the preceding
; apostrophe, it is best to incorporate this command in the menu with the
; apostrophe included to make it a quick "single pick" invokation. Thirdly,
; as the (LASTN) function is not nested within (C:LASTN), it can be called
; (with an integer argument) by other programs. As an example, to set symbol
; SS1 to a selection set containing the last 5 objects created, use:
;
; (setq SS1(lastn 5))
;
;      Any program that utilizes the (LASTN) function should, of course, check
; to see if it is already loaded and if not, load it. The following AutoLISP
; code would be satisfactory in most cases:
;
; (if(not LASTN)(load "LASTN"))
;
;      Note that although AutoCAD's "Last" option selects the last drawn
; object visible, at least partially, on screen, LASTN always selects the
; last n drawn objects, whether visible on screen or not. This includes
; objects on layers that are OFF or FROZEN. Objects on LOCKed layers are
; also selected but cannot be edited whereas objects on FROZEN or OFF layers
; can be edited. Caution: don't specify a value higher than the number of
; objects you have created in the current space (Paper or Model) since you
; last entered that space ie. changed TILEMODE - the results won't be what
; you want.
;;*****************************************************************************
(defun lastn (INT2 / SS2 SSL2)             ;define function to take 1 argument
(setq SS2 (ssadd))                         ;set SS2 to an empty selection set
(repeat INT2                                               ;repeat INT2 times
 (if (entlast)
  (progn
   (ssadd (entlast) SS2)          ;add last undeleted object to selection set
   (entdel (entlast))                           ;delete last undeleted object
  )
 )
)
(setq SSL2 (1- (sslength SS2)));set SSL2 to 1 less than size of selection set
 (while (>= SSL2 0)              ;while SSL2 is greater than or equal to zero
 (entdel (ssname SS2 SSL2))         ;undelete SSL2'th object in selection set 
 (setq SSL2 (1- SSL2))                                         ;decrement SL2
)
SS2                                 ;return selection set to calling function
)                                                        ;end (lastn) function
(defun C:loo (/ COUNT2)                                     ;define function
;set COUNT2 to number of objects
(setq COUNT2 (getint "\nEnter number of objects: "))
(if (= 0 (getvar "CMDACTIVE"))                 ;if no other command is active
 (progn                                                                 ;else
  (command "._SELECT" (lastn COUNT2) "")       ;run SELECT command and (lastn)
  (princ)                                                       ;exit quietly
 )
 (lastn COUNT2)                          ;call (lastn) function with argument
)
)

(setq lastItem (entlast))
;; do your processing
(setq ssetItems (ssadd))
(while (setq lastItem (entnext lastItem))
(ssadd lastItem ssetItems)
)
(sssetfirst nil ssetItems)

(defun c:CopyMWithSelect( / lastItem ssetItems )
(setq lastItem (entlast))
(command "_COPY" pause "" "_M")
(while (> (getvar "CMDACTIVE") 0)
 (command pause)
)
(setq ssetItems (ssadd))
(while (setq lastItem (entnext lastItem))
 (ssadd lastItem ssetItems)
)
(sssetfirst nil ssetItems)
(princ)
)