Which Event When i close app in iOS?

This delegete will be called when your application is going to terminate.

- (void)applicationWillTerminate:(UIApplication *)app
{
}

If you are using iOS 4 or greater and with multi-tasking support, applicationWillTerminate will not be called.

For receiving the terminate event you need to add UIApplicationExitsOnSuspend key on your info.plist

Check this article for a good understanding about application events.

Without mutitasking

With mutitasking


You may want to implement the

- (void)applicationWillTerminate:(UIApplication *)app;

method in your app delegate.

(Documentation)


You can handle it in

    - (void)applicationWillTerminate:(UIApplication *)application

which tells the delegate when the application is about to terminate.

Alternatively, you can listen to to the UIApplicationWillTerminateNotification notification.

See also: UIApplicationDelegate Protocol Reference