iPhone 4s stuck on black screen with functioning camera

I would say it is a software glitch. If you haven't tried it, try a reset, hold the sleep/wake and home buttons together until you see the Apple logo and then release. The phone will restart. See if that corrects it.

Go to the apps that are open (double click home button) and close them all.Then do the reset

Perfect. Thanks!

you're welcome

Turn off your iphone for a minute, then back on.. It worked for me! Thanks

Thanks, closed all apps and did a reset and my camera works again. Since I'm on vacation I am VERY happy to find a solution that didnt' need my computer OR access to an Apple Store! Great work.

same issue. closing all apps and resetting is fine, but is there a real solution? one that prevents the issue from continuing to arise, as it does every few days?

If this is arrising every few days, then I would say you have something more than a regular software glitch. The next step in user troubleshooting is a restore. First from a backup, then as a new device. I tend to believe this is an issue in iOS, I would try from a backup first. Make sure all of your data is backed up, synced to the computer you use and pictures are imported to the computer. That way if anything is lost in the process, it is on the computer for the restore. If doing it from the backup doesn't work, then restore as a new device. If the error still exists, then I recommend making an appointment at the Apple Store Genius bar ,as it would then seem to be a hardware issue.

all good worked perfectly thanks

I'm glad you got it going.