Test for an XRef

Does anyone know if you can Test (via Lisp) in a drawing to see if it has an
Xref or not?

I've a program I wrote which opens selected DWG files... I clean them up, etc.
What I want to do is IF the drawing has an Xref (ie a Border in Paperspace),
to set TileMode to 1... if no Xref... leave it as Model Space.

But I can't see how to do this... any thought?

Regards,

Bruce

 

Step with (tblnext "BLOCK" T) and (tblnext "BLOCK") through the block
table an check the value of dxf code 70: if it is >=4 it is some kind
of xref.

 

More correctly, you should do a bitwise evaluation of code 70. If the "4"
bit is set, the block is an XRef:

(if (= (logand (cdr (assoc 70 dat)) 4) 4)
(alert "This is an XREF")
(alert "This is a normal Block")
)

Code 70 may be greater than 4, even though the 4 bit is not set; individual
bit values currently in use go as high as 64. See the Customization Guide
section of HELP.
___

 

Thank you Bob...

Bruce

 

Thanks for the correction!

Bruce