startUpdatingLocation 仅在 wifi 开启时有效，但仅在 3G 开启时无效

Question

我试图获取用户当前位置的经度/纬度，我的代码就是这样：

MyLocationManager.h

@interface MyLocationManager : NSObject

+(MyLocationManager*)sharedInstance;
-(void)checkAndStartLocationManager;
-(void)stopUpdatingLocation;
@end

MyLocationManager.m

+ (MyLocationManager*)sharedInstance
{
    static id  _sharedInstance = nil;

    static dispatch_once_t oncePredicate;
dispatch_once(&oncePredicate, ^{
    _sharedInstance = [[self alloc] init];
    MyLocationManager *instance = _sharedInstance;
    instance.locationManager = [CLLocationManager new];
    instance.locationManager.delegate = instance;
    instance.locationManager.distanceFilter = 100;
    instance.locationManager.desiredAccuracy = kCLLocationAccuracyBest;
    instance.locationManager.pausesLocationUpdatesAutomatically = YES;
    instance.locationManager.activityType = CLActivityTypeOtherNavigation;
});
return _sharedInstance;
}

-(void)checkAndStartLocationManager
{
switch([CLLocationManager authorizationStatus])
{
    case kCLAuthorizationStatusAuthorizedWhenInUse:
        [self startUpdatingLocation];
        break;

    case kCLAuthorizationStatusNotDetermined:
            if ([self.locationManager respondsToSelector:
                 @selector(requestWhenInUseAuthorization)])
            {
                [self.locationManager requestWhenInUseAuthorization];
            }
        }
        break;

    case kCLAuthorizationStatusRestricted:
        break;

    case kCLAuthorizationStatusDenied:
        break;

    case kCLAuthorizationStatusAuthorizedAlways:
        [self startUpdatingLocation];
        break;

        default:
        break;
}
}

-(void)startUpdatingLocation
{
  [self.locationManager startUpdatingLocation];
}

- (void)locationManager:(CLLocationManager *)manager
didChangeAuthorizationStatus:(CLAuthorizationStatus)status
{
switch([CLLocationManager authorizationStatus])
{
    case kCLAuthorizationStatusAuthorizedWhenInUse:
        [self startUpdatingLocation];
        break;

    case kCLAuthorizationStatusNotDetermined:
        break;

    case kCLAuthorizationStatusRestricted:
        break;

    case kCLAuthorizationStatusDenied:
        break;

    case kCLAuthorizationStatusAuthorizedAlways:
        [self startUpdatingLocation];
        break;

        default:
        break;
}
}

- (void)locationManager:(CLLocationManager *)manager didUpdateLocations:    (NSArray *)locations
{
    CLLocation *location = [locations lastObject];
    NSString*locationInfo = [NSString stringWithFormat:@"lat - %f, lon -  %f", location.coordinate.latitude, location.coordinate.longitude];
    NSLog(@"Location is %@", locationInfo);
   [self.locationManager stopUpdatingLocation];
}

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

我正在使用 ios 8 并在 iphone 5 设备上进行了测试。每当我打电话时，

[[MyLocationManager sharedInstance] checkAndStartLocationManager];

如果手机上的wifi是开的，那么只有

didUpdateLocations 

正在被调用。 如果 wifi 处于关闭状态并且只有 3G 处于打开状态，那么我 总是收到错误，

Error Domain=kCLErrorDomain Code=0 "操作无法完成。(kCLErrorDomain error 0.)"

请帮忙！！！

Answer 1

设备使用 WiFi 通过众包热点快速确定位置，尽管结果可能不准确。当您禁用 WiFi 时，唯一剩下的可能性就是使用 GPS 模块。但是，如果您在某些建筑物中或 GPS 信号不够强，则需要更多时间来确定您的位置，并且您会在一段时间内收到该消息