iphone CLLocationmanager区域监控回调未触发 [英] iphone CLLocationmanager Region monitoring callbacks not triggered

问题描述

我正在尝试使用监控区域来跟踪用户是否访问过地标。
位置管理器在视图控制器中初始化以及视图控制器的viewdidload中的mapkit

I am trying to use monitoring regions to track if users have visited landmarks. the location manager is initialized in a viewcontroller along with a mapkit

：

if (self.locationManager == nil)
{
    //        NSLog(@"creating location manager");
    self.locationManager = [[CLLocationManager alloc] init];
    locationManager.delegate = self;
    locationManager.desiredAccuracy = kCLLocationAccuracyBestForNavigation;
    locationManager.distanceFilter = kCLDistanceFilterNone;
}


NSSet* set=[locationManager monitoredRegions];

if ([CLLocationManager regionMonitoringAvailable] && [CLLocationManager regionMonitoringEnabled]) {
    NSLog(@"region monitoring okay");
    NSLog(@"monitored regions: %@",set);
} 

我得到NSLogs区域监控好和所有区域正确。

i get the NSLogs "region monitoring okay" and all the regions correctly.

添加区域就像这样做

double metres=20.0;
CLLocationDistance dist=metres;
CLLocationAccuracy acc=1.0;

CLRegion *reg=[[CLRegion alloc] initCircularRegionWithCenter:coordinate radius:dist identifier:landmarkObj.landmarkName];

[locationManager startMonitoringForRegion:reg desiredAccuracy:acc];

但回调都没有被触发

 - (void)locationManager:(CLLocationManager *)manager didEnterRegion:(CLRegion *)region
{
    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Entered" 
                                                    message:region.identifier
                                                   delegate:self
                                          cancelButtonTitle:@"OK"
                                          otherButtonTitles:nil, nil];
    [alert show];
}

- (void)locationManager:(CLLocationManager *)manager didExitRegion:(CLRegion *)region
{
    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Exited" 
                                                    message:region.identifier
                                                   delegate:self
                                          cancelButtonTitle:@"OK"
                                          otherButtonTitles:nil, nil];
    [alert show];
}

- (void)locationManager:(CLLocationManager *)manager didStartMonitoringForRegion:(CLRegion *)region
{
    NSLog(@"started monitring for region: %@",region);
}

- (void) locationManager:(CLLocationManager *)manager monitoringDidFailForRegion:(CLRegion *)region withError:(NSError *)error
{
    NSLog(@"%@",error);
}

更新位置但工作正常。

[locationManager startUpdatingLocation];

按预期触发回调didUpdateToLocation

triggers the callback didUpdateToLocation as expected

更新：使用didUpdatToLocation来监控区域。
仍然有兴趣知道为什么这不起作用，看起来很少有人在区域监控方面取得了成功

Update: used didUpdatToLocation to monitor for regions instead. still interested to know why this would not work though, looks like few have had success with region monitoring

推荐答案

区域跟踪内容用于低粒度位置跟踪，并在单元位置边界上触发，因此如果不跨越单元格边界，则永远不会检查区域。我有同样的问题，并研究了这个和一个不同的网站有关于此的评论指向这个苹果论坛：

the region tracking stuff is for low granularity position tracking and is triggered on cell location boundaries, so if you don't cross a cell boundary, you will never get your regions checked. I had the same issues and researched this and a different website had a comment about this which pointed to this apple forum:

https://devforums.apple.com/message/251046#251046

如果您阅读了所有评论，您将理解为什么这不起作用。

If you read all the comments you will understand why this is not working.

我正在尝试解决我定义自己的NSSets以包含跟踪的CLRegions和占用CLRegions的问题。然后当我得到一个locationManager：didUpdateToLocation：fromLocation：callback时，我检查我跟踪集合中的所有区域，看看我是不在inRegions集合中，但现在是在跟踪区域（添加到inRegions并使用enterRegion回调）或如果我在地区但现在不是（从inRegions中移除并使用exitRegion回调）。现在正在进行中。

I am trying a work around where I define my own NSSets to contain tracked CLRegions and occupied CLRegions and then when I get a locationManager:didUpdateToLocation:fromLocation: callback, I check all the regions in my tracked set to see if I was NOT in the inRegions set but now am in the tracked region (add to inRegions and call back with enterRegion) or if I was inRegion but now am not (remove from inRegions and call back with exitRegion). It is a work in progress now.

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