请大佬们帮我看看下面这段代码为啥不能实现延伸，多谢啦

陈同学

• (defun c:ec()
•   (setq ss(ssget))
•     (setq s1 (ssname ss 0))
•     (setq s2 (ssname ss 1))
•   (command "extend" s1 "" s2 "")
•   (princ)
• )
  

jun353835273

命令行单步调试看提示

2. 
   
3. (defun c:ec()
   
4.   (setq ss(ssget))
   
5.   (setq s1 (ssname ss 0))
   
6.   (command "extend" s1 "" "c" (GETPOINT "\nPick the First point") (GETPOINT "\nPick the Second point") "" )
   
7. (princ)
   
8. )

<br /> (defun c:ec()<br />   (setq ss(ssget))<br />   (setq s1 (ssname ss 0))<br />   (command "extend" s1 "" "c" (GETPOINT "\nPick the First point") (GETPOINT "\nPick the Second point") "" )<br /> (princ)<br /> )