使用CLLocationManager监控超过20个商店

Question

我正构建一个应用程序，每当他通过我的客户商店时都会通知用户。

问题是它有超过20个商店，CLLocationManager允许同时监控多达20个商店。

所以我所做的就是找到距离用户当前位置最近的20家商店，但由于某种原因它是不准确的。

就像第一次运行应用程序时，locationManager正确监控区域。

有人可以查看我的代码并告诉我他是否认为错误？谢谢！

我的代码（滚动查看所有代码）：

-(void)sortClosestStores
{
    [self.allStores sortUsingComparator:^NSComparisonResult(id  _Nonnull obj1, id  _Nonnull obj2) {
    CLLocation *location1=[[CLLocation alloc] initWithLatitude:((Store*)obj1).geoPoint.latitude longitude:((Store*)obj1).geoPoint.longitude];
    CLLocation *location2=[[CLLocation alloc] initWithLatitude:((Store*)obj2).geoPoint.latitude longitude:((Store*)obj2).geoPoint.longitude];

    float dist1 =[location1 distanceFromLocation:self.userLocation];
    float dist2 = [location2 distanceFromLocation:self.userLocation];
    if (dist1 == dist2) {
        return NSOrderedSame;
    }
    else if (dist1 < dist2) {
        return NSOrderedAscending;
    }
    else {
        return NSOrderedDescending;
    }
}];

    if (self.twentyClosestStores==nil) {
    self.twentyClosestStores=[NSMutableArray array];
    }

    if (self.previousTwentyStores==nil) {
        self.previousTwentyStores=[NSMutableArray array];
    }
    self.previousTwentyStores=self.twentyClosestStores;

    NSLog(@"%f,%f",self.userLocation.coordinate.latitude,self.userLocation.coordinate.longitude);
    for (int i = 0; i < 20; i++) {
        [self.twentyClosestStores addObject:[self.allStores objectAtIndex:i]];
    }
    Store *nearest=[self.twentyClosestStores firstObject];

}

-(void)locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray<CLLocation *> *)locations
{
    NSLog(@"%f,%f",self.userLocation.coordinate.latitude,self.userLocation.coordinate.longitude);
    self.userLocation=self.locationManager.location;
}

-(void)locationManager:(CLLocationManager *)manager didEnterRegion:(CLRegion *)region
{
    NSLog(@"Entered");
}

-(void)stopMonitoringStores
{
    for (Store *currentStore in self.twentyClosestStores) {
        CLCircularRegion *region=[currentStore createCircularRegion];
        [self.locationManager stopMonitoringForRegion:region];
    }
}

-(void)locationManager:(CLLocationManager *)manager didExitRegion:(CLRegion *)region
{
    if (self.allStores.count>=1171) {
         [self sortClosestStores];
    }
     if (self.previousTwentyStores!=nil||self.previousTwentyStores.count==0) {
         [self stopMonitoringStores];
     }
[self startMonitoringClosestStores];
}

-(void)startMonitoringClosestStores
{
    [self stopMonitoringStores];

    if (![CLLocationManager isMonitoringAvailableForClass:[CLCircularRegion class]]) {
        NSLog(@"Monitoring is not available for CLCircularRegion class");
    }

    for (Store *currentStore in self.twentyClosestStores) {
        CLCircularRegion *region=[currentStore createCircularRegion];
        [self.locationManager startMonitoringForRegion:region];
    }
}

你能看错吗？

非常感谢！