iPhone- iOS本地通知与滑动到期

Question

Can i create a Local notfication in an iphone app with sliding expiration.

My problem statement is that i want to show user a local notification in case the app is terminated by IOS or by an exception.

So to achieve this i am trying to do the following

Create a thread that runs every 5 seconds. This thread first cancels all scheduled notification and then schedules a notification with currenttime +10 seconds.

This way if the app gets killed then the user will be notified within 10 seconds that the app is terminated.

Please advise

Thanks,Amit

Answer 1

Implement the below method...

- (void)applicationWillTerminate:(UIApplication *)application {

    // Cancel all local notification.

    [[UIApplication sharedApplication] cancelAllLocalNotifications]; 

   // Create an future date with 10+ second

    NSDateComponents *dateComponents = [[NSDateComponents alloc] init];
    [dateComponents setSecond:10];
    NSCalendar *calendar = [NSCalendar currentCalendar];
    NSDate *fireDate = [calendar dateByAddingComponents:dateComponents toDate:[NSDate date] options:0]; 

    // Scheduled the notification

    UILocalNotification *localNotification = [[UILocalNotification alloc] init];
    [localNotification setFireDate:fireDate];
    [localNotification setTimeZone:[NSTimeZone defaultTimeZone]];
    [localNotification setAlertBody:@"Application Terminated"];
    [[UIApplication sharedApplication] scheduleLocalNotification:localNotification];
}

UPDATE

From the Apple Doc

For apps that do not support background execution or are linked against iOS 3.x or earlier, this method is always called when the user quits the app. For apps that support background execution, this method is generally not called when the user quits the app because the app simply moves to the background in that case. However, this method may be called in situations where the app is running in the background (not suspended) and the system needs to terminate it for some reason .