In my iOS app's Settings screen, there is one setting which is quite fundamental. I wish to inform users about this with a UIAlertView.
Preferably I would display this when the back button is pressed (and thus they are finished editing their settings). However, is this possible, or even allowed by Apple? If so, how?
My second choice would be to show the UIAlertView as soon as the setting is changed, but if this is possible its not really a preference. And if it is possible, how do I do it?
Edit - 2nd August 2012 : My app has its own Settings screen in addition to the built in Settings screen, so my question applies to both screens. Also, note that the setting is a UISwitch.
Also, I preferably would like a cancel button on the UIAlertView that allows the user to NOT leave the settings screen once they have read the warning. Is this possible?