CAD中直接画箭头的简便技巧

方法1：投机的方法

先标注一个尺寸,再把该尺寸打散,删除其他的,只留一个箭头就可以了。然后就可以旋转,复制,想怎么样就怎么样了。

方法2：在autocad中直接画箭头

在CAD中直接画箭头的命令的一个方法！！！

    众所周知，在天正中可直接绘制箭头，而在AutoCAD中不可。在命令行直接输入命令就可画出你想要的尺寸的箭头的方法，具体实施如下：

1、首先拷贝下列lisp程序，用ar为名以记事本格式保存，然后改后缀名为.lsp，作为一个lisp程序文件；程序如下：

(defun ureal (bit kwd msg def / inp)

(if def

(setq msg (strcat "n" msg "<" (rtos def) ">: ")

bit (* 2 (fix (/ bit 2)))

)

(if (= " " (substr msg (strlen msg) 1))

(setq msg (strcat "n" (substr msg 1 (1- (strlen msg))) ": "))

(setq msg (strcat "n" msg ": "))

)

)

(initget bit kwd)

(setq inp (getreal msg))

(if inp inp def)

)

(defun upoint (bit kwd msg def bpt / inp)

(if def

(setq pts (strcat

(rtos (car def))

","

(rtos (cadr def))

(if

(and (caddr def) (= 0 (getvar "FLATLAND")))

(strcat "," (rtos (caddr def)))

""

)

)

msg (strcat "n" msg "<" pts ">: ")

bit (* 2 (fix (/ bit 2)))

)

(if (= " " (substr msg (strlen msg) 1))

(setq msg (strcat "n" (substr msg 1 (1- (strlen msg))) ": "))

(setq msg (strcat "n" msg ": "))

)

)

(initget bit kwd)

(setq inp

(if bpt

(getpoint msg bpt)

(getpoint msg)

)

)

(if inp inp def)

)

(setq cm(getvar "cmdecho"))

(setvar "cmdecho" 0)

(defun C:AR ( / #dwgsc w v pt1 pt2 pt3 )

(if(= arscl nil)(setq arscl 0.1875))

(setq #dwgsc(getvar "DIMSCALE")

W(getvar "PLINEWID")

V(getvar "OSMODE")

L(getvar "CLAYER"))

(setq arscl(ureal 7 "" "请输入箭头长度" arscl))

(setvar "OSMODE" 1)

(setq pt1 (upoint 1 "" "指定箭头顶点" nil nil))

(setvar "OSMODE" 512)

(setq PT(entsel "n选择直线上要画箭头一端的任意一点"))

(setq PT2(cadr PT))

(setq ED(entget(car PT)))

(setq PT3 (polar PT1 (angle PT1 PT2) (* #dwgsc arscl)))

(command "PLINE" pt1 "w" "0" (* #dwgsc (/ arscl 3)) pt3 "")

(setvar "OSMODE" V)

(setvar "CLAYER" L)

(setvar "plinewid" W)

(princ)

)

(setvar "cmdecho" cm)

(princ)

2、将ar.lsp拷贝至CAD目录下的support目录下；

3、在CAD目录下的support目录内找到文件acad2000doc.lsp文件（CAD2002下，在别的版本CAD中可能不是这个名，这是CAD的自动加载文件）；

4、用记事本程度打开acad2000doc.lsp文件，加入一行：(load "ar.lsp")

（注意字符要为英文字符）

5、保存后，重新启动CAD，在命令行就可输入ar命令直接画箭头了。