I have a selector to show UIAlertView
asking user if want to retry upload images after NotificationCenter post a notification with observename.
[[NSNotificationCenter defaultCenter] postNotificationName:kNOTIFICATION_PHOTOS_UPLOAD_RETRY object:nil];
But because of the notification received more than one, so will show as many as notifications received. Is there a best practice to show alert view only once?