I have an open bounty question (qtcreator can't find qt) and solved the problem.
In those cases you answer your own question but mine has open bounty, what will happen to the bounty? I don't think I'll get it, right?
You cannot give yourself a bounty (and its something that would be abused anyway)
Refunding bounties is really on a case by case basis. In theory, once you have offered a bounty, you really arn't meant to get the reputation back
There's a few options here, really. As a one off thing, under exceptional circumstances, we do refund bounties. Posting a detailed, high quality (and repeatable) answer, and explaining your circumstances in a flag is definately one option. In general, bounties arn't meant to be refunded (but of course there's exceptions), so don't make a habit of it -It would really depend on how the mod who handles the flag sees it, and there's no guarantee of a refund.
I usually wait for someone else to answer (or mention that there's a open bounty, and point folk at the right direction on chat!), for reasons for fair play when this happens. I do have rep to burn, so to speak, so... Seems a much nicer thing to do.