在ios中安排4个后续本地通知的问题

Question

我正在尝试创建由静态时差分隔的4种不同的本地通知。意思是，第一个通知将在开始时间触发，然后每X秒触发另一个本地通知（总共4个）。

仅创建2个本地通知的问题而不是4。我不明白为什么。

double timeToAdd=0;

double timeDifference=[album.end_time timeIntervalSinceDate:album.start_time]/4;
for (int i = 1; i <= 4; i++)
{
   NSDate *dateToNotify = [NSDate dateWithTimeInterval:timeToAdd sinceDate:album.start_time];

   UILocalNotification* localNotification = [[UILocalNotification alloc] init];
   localNotification.fireDate = dateToNotify;
   localNotification.alertBody = @"Click to sync";
   localNotification.alertAction=@"Click to sync";
   localNotification.soundName = UILocalNotificationDefaultSoundName;
   localNotification.userInfo =@{@"id":[ album.id stringByAppendingString:album.code]};
   [[UIApplication sharedApplication] scheduleLocalNotification:localNotification];
   timeToAdd+=timeDifference;
}