Here is another way (limited testing)
; Jason Piercey . January 12th, 2004
; function to determine if a layerstate exists
; Arguments:
; [document] - vla-object, document object
; [layerstate] - string, layerstate name
; return: xrecord object if successful
; example:
; (layerstate-p (vla-get-activedocument (vlax-get-acad-object)) "test") (defun layerstate-p (document layerstate / res) (if (vl-catch-all-error-p (setq res (vl-catch-all-apply '(lambda (vla-item (vla-item (vla-getextensiondictionary (vla-get-layers document)) "Acad_Layerstates" ) layerstate ) ) ) ) ) (vl-catch-all-error-message res) res )
)