Добавьте это в свой AppDelegate:
- (void)applicationWillEnterForeground:(UIApplication *)application {
/*
Called as part of transition from the background to the active state: here you can undo many of the changes made on entering the background.
*/
}
- (void)applicationDidBecomeActive:(UIApplication *)application {
/*
Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface.
*/
}
viewWillAppear не вызывается, потому что, когда приложение находится в фоновом режиме / приостановлено, представление все еще существует.