How to find out which segment of LWPOLYLINE is selected?

Hello to everybody here!
----------------------------
Do you can tell me,
how to find out which segment of LWPOLYLINE is selected?

I figured out to
1. (entget ...) the selected LWPOLYLINE;
2. reconstruct it with LINEs and ARCs;
3. number these new entities;
4. select some new entity with (entsel ...);
5. find out which element was selected by its number...

But I think there must be a simple way to do it...

Thank you all again!

 

Here's an example of how you can do this. The segment index is 0 based, so
if you want to report that the first segment was selected add 1 to this
result. Yes, this code can be condensed, but I show it like this so you can
clearly see the steps taken.

(setq pline (entsel))
(setq pick (cadr pline))
(setq plObj (vlax-ename->vla-object (car pline)))
(setq pick2 (vlax-curve-getclosestpointto plobj pick))
(setq param (vlax-curve-getparamatpoint plObj pick2))
(setq segment (fix param))

 

Thank you Jeff!!!
------------------
Sorry for delay but I missed my Internet connection for a while.

I hoped there is some way in VisualLISP.

Thank you again!

 

Hi Jeff!
----------
I don't understand something or I do something wrong?

I draw the LWPOLYLINE then run your code.
For example I pick the first segment of LWPOLY
and get for the result some 4-digit number...

What is it???

******************************************************
Command: (setq pline (entsel))

Select object: (<Entity name: 40071140> (18733.0 12086.0 0.0))

Command: (setq pick (cadr pline))
(18733.0 12086.0 0.0)

Command: (setq plObj (vlax-ename->vla-object (car pline)))
#<VLA-OBJECT IAcadLine 029da1a4>

Command: (setq pick2 (vlax-curve-getclosestpointto plobj pick))
(18760.2 12059.6 0.0)

Command: (setq param (vlax-curve-getparamatpoint plObj pick2))
5701.33

Command: (setq segment (fix param))
5701

******************************************************

From the Help:

(vlax-curve-getParamAtPoint curve-obj point)
===================================

Return Values:
---------------
A real number representing a parameter, if successful, otherwise nil.

******************************************************


Help me!.. : (

 

Hi Alexander,
I'm glad you got your internet connection back

The param will return the length from the start to the picked point if you
select a line. You apparently mistakenly selected a line, not a LWPolyline:

Try it again with a polyline

 

Try it again with a polyline

Oh!.. Jeff...
-------------
I'm so sorry... ;-(

YOU WERE ABSOLUTELY RIGHT!
You know it was the Sunday evening...

Thank you again for your PATIENCE!!!