UIAlertViewDelegate clickedButtonAtIndex: usefulness?

Question

The UIAlertViewDelegate protocol defines two methods, alertView:clickedButtonAtIndex: and alertView:didDismissWithButtonIndex:, which seem to me to be identical in usefulness.

Why is there a clickedButtonAtIndex and a didDismissButtonWithIndex when they both do the same thing? I realize there is also a willDismissButtonWithIndex that happens before the alert view is dismissed, but is there any reason to use clickedButtonAtIndex instead of didDismissButtonWithIndex?

Answer 1

Hi,

The "alertView:clickedButtonAtIndex:" is called when the user clicks a button on an alert view whereas the "alertView:didDismissWithButtonIndex:" is called after an alert view is dismissed from the screen. (see the UIAlertViewDelegate Protocol Reference)

The difference is minimal but it allows you to do something before or after animation.

Answer 2

I found a more useful difference between the two:

When showing a UIAlertView, and the device goes to sleep, alertView:didDismissWithButtonAtIndex: gets called, even though the alert view is not actually dismissed. It is shown again once the device wakes up. alertView:clickedButtonAtIndex: is only called when the user clicks one of the buttons.