计算喷头数量

计算图块的数量，特别适用计算喷头数量
;;计算图块数目
;;nb.lsp

(defun c:nb ()
(graphscr)
(setq oce (getvar "cmdecho"))
(setvar "cmdecho" 0)

(setq r1 5 h1 5)

(setq
b1 (entsel "\n选取要计算的图块：")
b2 (car b1)
b3 (entget b2)
b6 (assoc 2 b3)
b7 (cdr b6)
b8 (ssget (list b6))
b9 (sslength b8)
)
(setvar "cmdecho" oce)
(princ "\n图块")
(princ b7)
(princ "数目是")
(princ b9)
(princ)
)