ios - 未调用 CoreLocation 区域委托(delegate)

Question

我在使用 iOS 5 中的 CoreLocation 区域委托(delegate)方法时遇到问题，无论是在模拟器中还是在设备上。我正在尝试添加一个监控区域，然后等待 didStartMonitoring 委托(delegate)回调。很少，它工作正常。但是，通常 didStartMonitoring 和 monitoringDidFail 都不会被调用。该区域会添加到 monitoredRegions。委托(delegate)对象设置正确，通常会调用 didEnterRegion 和 didExitRegion。位置管理器永远不会被释放。这是在main thread .我已经检查了所有我能想到的条件。

-(id) init
{
   self = [super init];
   if( self ) {
      NSLog( @"initializing location manager" );
      self.locationManager = [[CLLocationManager alloc] init];
      locationManager.delegate = self;
      [locationManager startUpdatingLocation];
   }
   return self;
}

-(void) startMonitoringRegion
{
   BOOL monitoring = NO;    
   if ( [CLLocationManager regionMonitoringAvailable] ) {
      if ( [CLLocationManager regionMonitoringEnabled] ) {
         if( [CLLocationManager authorizationStatus] == kCLAuthorizationStatusAuthorized ) {
            monitoring = YES;
         } else {
            NSLog( @"app is not authorized for location monitoring" );
         }
      } else {
         NSLog( @"region monitoring is not enabled" );
      }
   } else {
      NSLog( @"region monitoring is not available" );
   }
   if( !monitoring ) return;

   CLRegion *region = [[CLRegion alloc] initCircularRegionWithCenter:locationManager.location.coordinate 
                                                          radius:50
                                                      identifier:@"majorRegion"];
   NSLog( @"trying to start monitoring for region %@", region );
   [locationManager startMonitoringForRegion:region desiredAccuracy:kCLLocationAccuracyBest];
}

-(void)     locationManager:(CLLocationManager*)manager 
didStartMonitoringForRegion:(CLRegion*)region
{
   NSLog( @"region monitoring started" );
}

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

- (void)locationManager:(CLLocationManager *)manager didFailWithError:(NSError *)error
{
   NSLog( @"location manager failed" );
}

有人有什么想法吗？我可以处理这个问题，但似乎 didEnterRegion 和 didExitRegion 委托(delegate)方法有时也不一致，这对我来说是个大问题。

编辑:我可以在单个应用程序委托(delegate)中复制此功能——没有自定义对象或任何东西。请参阅下面的实现。区域被添加(打印时可见)，但 didStartMonitoringRegion 永远不会被调用。

@implementation AppDelegate

@synthesize window = _window;
@synthesize locationManager;

-(void) startMonitoringRegion
{
   BOOL monitoring = NO;    
   if ( [CLLocationManager regionMonitoringAvailable] ) {
      if ( [CLLocationManager regionMonitoringEnabled] ) {
         if( [CLLocationManager authorizationStatus] == kCLAuthorizationStatusAuthorized )  {
            monitoring = YES;
         } else {
            NSLog( @"app is not authorized for location monitoring" );
         }
      } else {
         NSLog( @"region monitoring is not enabled" );
      }
   } else {
      NSLog( @"region monitoring is not available" );
   }
   if( !monitoring ) return;

   CLRegion *region = [[CLRegion alloc] initCircularRegionWithCenter:locationManager.location.coordinate 
                                                              radius:50.
                                                          identifier:@"majorRegion"];
   NSLog( @"trying to start monitoring for region %@", region );
   [locationManager startMonitoringForRegion:region desiredAccuracy:kCLLocationAccuracyBest];
}

-(void) printMonitoredRegions
{
   NSLog( @"printing regions:" );
   for( CLRegion* region in locationManager.monitoredRegions )
      NSLog( @"%@", region );
}


- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
   NSLog( @"initializing location manager" );
   self.locationManager = [[CLLocationManager alloc] init];
   locationManager.delegate = self;
   [locationManager startUpdatingLocation];

   [self startMonitoringRegion];
   [self performSelector:@selector(printMonitoredRegions) withObject:nil afterDelay:2.];

   return YES;
}


- (void)locationManager:(CLLocationManager *)manager 
    didUpdateToLocation:(CLLocation *)newLocation 
           fromLocation:(CLLocation *)oldLocation
{
   //NSLog( @"location updated" );
}

-(void)     locationManager:(CLLocationManager*)manager 
didStartMonitoringForRegion:(CLRegion*)region
{
   NSLog( @"region monitoring started" );
}

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

-(void) locationManager:(CLLocationManager*)manager didExitRegion:(CLRegion*)region
{
   NSLog( @"did exit region" );
}

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

- (void)locationManager:(CLLocationManager *)manager didFailWithError:(NSError *)error
{
   NSLog( @"location manager failed" );
}

@end

日志:

2012-02-21 10:53:50.397 locationtest[64440:f803] initializing location manager
2012-02-21 10:53:50.412 locationtest[64440:f803] trying to start monitoring for region (identifier majorRegion) <LAT,LONG> radius 50.00m
2012-02-21 10:53:52.414 locationtest[64440:f803] printing regions:
2012-02-21 10:53:52.416 locationtest[64440:f803] (identifier majorRegion <LAT,LONG> radius 50.00m

编辑 2:我刚刚注意到 iOS implementation CLLocationManagerDelegate 协议(protocol)与 Mac implementation 略有不同-- 值得注意的是，Mac 没有 didStartMonitoringRegion。有没有可能我不小心使用了 Mac 库而不是 iOS 库？

Answer 1

看看 Apple 是怎么说的:

http://developer.apple.com/library/ios/#documentation/userexperience/conceptual/LocationAwarenessPG/CoreLocation/CoreLocation.html

测试您的应用的区域监控支持

在 iOS 模拟器或设备上测试区域监控代码时，要意识到区域事件可能不会在区域边界被跨越后立即发生。为防止虚假通知，iOS 在满足特定阈值条件之前不会发送区域通知。具体而言，用户的位置必须跨越区域边界并离开该边界最小距离，并在报告通知之前保持该最小距离至少 20 秒。

具体的阈值距离由硬件和当前可用的定位技术决定。例如，如果 Wi-Fi 被禁用，区域监控的准确性就会大大降低。但是，出于测试目的，您可以假设最小距离约为 200 米。