Topic: Create Field from 2 block attributes.

[LSElite]

Hey All

I am making a tagging program where the user clicks a block and places a tag at the cursor.
What I need for the Tag is an updating field.
the field needs to reference the attribute values and find the distance between the elevations.
eg:
100 and 500 = 400
-100 and 500 = 600
-500 and 0 = 500

I can do this however it would not make a field of the value.
Does anyone know if this can be achieved with a field or a diesel expression?

Cheers

[mianbaoche]

Code - Auto/Visual Lisp: [Select]

1. (defun c:kk()
2. (setq lst (list '(100 400) '(-100 400) '(100 -400) '(-100 -400)))
3. (mapcar '(lambda (x) (if (= (minusp (car x)) (minusp (cadr x)))
4.                        (abs (- (car x) (cadr x) ))
5.                        (+ (abs (car x))(abs (cadr x)))
6.                        )) lst)
7.   )

[LSElite]

So I have found most of what I need to make this work.
All i need now is how to find the VLA object for the attributes in the selected block.
Anyone know how to return all VLA Attribute Objects from a block?

[HasanCAD]

I believe this lisp will help
http://www.lee-mac.com/countattributevalues.html

[LSElite]

Thanks HasanCAD
I cant figure out how the attribute entities work though.
Ill keep working at it but a steer in right direction would be appreciated.
I just need the VLA-Entity for an attribute named "Elevation" in a selected block.

Cheers

[roy_043]

Code - Auto/Visual Lisp: [Select]

1. (vl-some
2.   '(lambda (attObj)
3.     (if (= (strcase (vla-get-tagstring attObj)) str)
4.       attObj
5.     )
6.   )
7.   (vlax-invoke blockRefObj 'getattributes)
8. )

[LSElite]

'GetAttributes was exactly what I was looking for.
Cheers Roy

[HasanCAD]

I believe this link will give you more help
http://www.lee-mac.com/attributefunctions.html

[LSElite]

Cheers Hansan