CAD二次开发 绘制螺纹 (defun c:luowen() (setq d(getreal “螺纹公称直径=”)) (setq r(/d 2)) (setq tt(getreal “螺距=”)) (setq l(getreal “螺纹长度=”)) (setq p0(getpoint “指定基点”)) (setq p01(list (n th 0 p0) (n th 1 p0) (-1(/tt 1.155)))) (setq p012(list (n th 0 p0) (n th 1 p0)1