Last time I was there (for a college bowl game, not a pro game) they had signs saying that weapons, and they specifically listed knives, as being prohibited. They also had individual security inspection. However, they were just going thru the motions as my son walked right in with a Spyderco Nomad clipped in his hip pocket in full view. That being said, there is no way I would risk it.
As far as the state, he wandered around for three days with the same arrangement and no one ever said a word to him.