iOS位置提醒应用程序错过某些位置

我们正在构建基于位置的提醒应用程序，它在10个案例中有7个案例有效。它只是错过了某些位置。你能建议一下这可能会有什么问题吗

下面是我们用于位置匹配的逻辑

-(void)locationChangeLogic {
      CLLocation *currentLocation = [[CLLocation alloc] initWithLatitude:latitudeTemp longitude:longitudeTemp];
    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
        // Perform long running process
        NSArray *arrayLocations = [[NSArray alloc] initWithArray:[[self db] getListOfLocations]];

        NSMutableArray *arrayToNotification = [[NSMutableArray alloc] init];

        if ([arrayLocations count] > 0) {
            for (NSDictionary *dict in arrayLocations) {
                CLLocation *newLocation = [[CLLocation alloc] initWithLatitude:[[dict valueForKey:@"latitude"] floatValue] longitude:[[dict valueForKey:@"longitude"] floatValue]];

                float miles = [[NSUserDefaults standardUserDefaults] floatForKey:@"miles"];

                CLLocationDistance distance = [currentLocation distanceFromLocation:newLocation];

                //Set matched objects and update flag
                if ((distance/1609.344) <= miles) {
                    if ([[dict valueForKey:@"isSelected"] integerValue] == 1) {
                        [arrayToNotification addObject:dict];
                    }
                    //Matched location FLAG will going to 0, so notification not get fire twice or repeatedly
                }else {
                    //The location which are not in current redius, we will make those location FLAG to 1, So when user enter in different location it will check for that
                }
            }
        }

        dispatch_async(dispatch_get_main_queue(), ^{
            if ([arrayToNotification count] > 0) {
                [self setAndFireLocalNotifications:arrayToNotification];
            }
        });
    });
}

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