安排许多UILocalNotification的最佳方式

Question

我正在尝试同时安排许多UILocalNotification个。我刷新了大量数据，需要取消之前的所有通知并重新创建它们。目前我有这个代码来取消和创建通知：

- (void)scheduleNotifications {
    NSDate *start = [NSDate date];
    // Cancel old notifications
    [NotificationHandler cancelNotificationsNamed:@"ScheduleNotification"];

    if (self.user.scheduleNotifications.boolValue) {
        for (NSInteger i = 0; i < self.user.scheduleDays.count; i++) {
            ScheduleDay *day = [self.user.scheduleDays objectAtIndex:i];
            for (SchedulePeriod *period in day.periods) {
                if (period.desc.length > 0) {
                    NSDateComponents *dateComponents = [[NSCalendar autoupdatingCurrentCalendar] components:NSCalendarUnitDay|NSCalendarUnitWeekday|NSCalendarUnitMonth|NSCalendarUnitYear fromDate:[NSDate date]];
                    dateComponents.day += 2 + i - dateComponents.weekday;
                    NSArray *timeComponents = [period.startTime componentsSeparatedByString:@":"];
                    NSInteger hour = [[timeComponents objectAtIndex:0] integerValue];
                    dateComponents.hour = hour < 7 ? hour + 12 : hour; // add 12 to hour if before 7 (assume afternoon)
                    dateComponents.minute = [[timeComponents objectAtIndex:1] integerValue] - 5;
                    NSDate *fireDate = [[NSCalendar autoupdatingCurrentCalendar] dateFromComponents:dateComponents];

                    if ([[NSDate date] compare:fireDate] == NSOrderedDescending) {
                        fireDate = [fireDate dateByAddingTimeInterval:604800]; // add a week if date is passed
                    }

                    [NotificationHandler scheduleNotificationNamed:@"ScheduleNotification"
                                                           forDate:fireDate
                                                           message:period.desc
                                                      repeatWeekly:YES];
                }
            }
        }
    }

    NSLog(@"%f sec", [[NSDate date] timeIntervalSinceDate:start]);
}

NotificationHandler.m：

+ (void)scheduleNotificationNamed:(NSString *)name forDate:(NSDate *)date message:(NSString *)message repeatWeekly:(BOOL)repeatWeekly {
    UILocalNotification *notification = [[UILocalNotification alloc] init];
    notification.userInfo = @{@"kNotificationName" : name};
    notification.fireDate = date;
    notification.alertBody = message;
    notification.timeZone = [NSTimeZone defaultTimeZone];
    if (repeatWeekly) {
        notification.repeatInterval = NSCalendarUnitWeekOfYear;
    }
    [[UIApplication sharedApplication] scheduleLocalNotification:notification];
}

+ (void)cancelNotificationsNamed:(NSString *)name {
    for (UILocalNotification *notification in [[UIApplication sharedApplication] scheduledLocalNotifications]) {
        if ([[[notification userInfo] objectForKey:@"kNotificationName"] isEqualToString:name]) {
            [[UIApplication sharedApplication] cancelLocalNotification:notification];
        }
    }
}

不幸的是，有时需要几秒钟才能取消并创建阻止UI的通知。还有更好的方法吗？