CLLocationManager跟踪错误的位置(Track Me)

Question

我在我的代码中实现Track me选项。CLLocationManager没有正常工作。当我启动应用程序保持在同一位置时，CLLocationManager在1分钟内变化约20-30米，然后我保持不变。

如果我改变我的位置跟踪同样的事情发生在开始1分钟CLLocationManager移动20-30分钟，然后移动与我的速度..

为什么会这样?

 - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {  
  self.locationManager = [[CLLocationManager alloc] init];
self.locationManager.delegate = self;
self.locationManager.distanceFilter = 0.0001;
self.locationManager.desiredAccuracy = kCLLocationAccuracyBest;
 }

-(void)start {

[self.locationManager startUpdatingLocation];    
}

 - (void)locationManager:(CLLocationManager*)manager
didUpdateToLocation:(CLLocation*)newLocation 
       fromLocation:(CLLocation*)oldLocation {
[self processLocationChange:newLocation fromLocation:oldLocation];
 }

 -(void)processLocationChange:(CLLocation*)newLocation fromLocation:oldLocation {
if (newLocation != oldLocation) {
    NSLog(@"Moved from %@ to %@", oldLocation, newLocation);
    CLLocation* lastKnownLocation = NULL;
    if ([self.locationPoints count] > 0) {
        lastKnownLocation = [self.locationPoints objectAtIndex:[self.locationPoints count] - 1];
    }
    else {
        lastKnownLocation = newLocation;
        self.bottomLeft = newLocation.coordinate;
        self.topRight = newLocation.coordinate;
    }
    // Check for new boundaries
    CLLocationCoordinate2D coords = newLocation.coordinate;
    if (coords.latitude < bottomLeft.latitude || coords.longitude < bottomLeft.longitude) {
        self.bottomLeft = coords;
        NSLog(@"Changed bottom left corner");
    }
    if (coords.latitude > topRight.latitude || coords.longitude > topRight.longitude) {
        self.topRight = coords;
        NSLog(@"Changed top right corner");
    }


    double speed = fabs(newLocation.speed);
    double deltaDist = fabs([newLocation distanceFromLocation:lastKnownLocation]);
    double newAvgSpeed = (self.totalDistance + deltaDist) / ((double)[self getElapsedTimeInMilliseconds] / 1000.0);
    double accuracy = newLocation.horizontalAccuracy;
    double alt = newLocation.altitude;
    NSLog(@"Change in position: %f", deltaDist);
    NSLog(@"Accuracy: %f", accuracy);
    NSLog(@"Speed: %f", speed);
    NSLog(@"Avg speed: %f", newAvgSpeed);


        self.totalDistance += deltaDist;
        self.currentSpeed = speed;
        self.avgSpeed = newAvgSpeed;
        self.altitude = alt;
        NSLog(@"Delta distance = %f", deltaDist);
        NSLog(@"New distance = %f", self.totalDistance);

        // Add new location to path
        [self.locationPoints addObject:newLocation];
        // Update stats display
        [self.first.start1 updateRunDisplay];
        // Update map view
        [self updateMap:lastKnownLocation newLocation:newLocation];
    }
}

Answer 1

我在我现在的计步器应用程序中遇到了同样的问题。我伸展了几天，撞了撞我的头。然后我发现CLLocationManager无法跟踪<5米的距离和位置生成更新。我保留了self.locationManager.distanceFilter =2.0;，它给了我位置更新，即使设备是静止的。所以我只是把距离过滤器改为5.0米，它开始工作得很好。试着用5米，它应该可以工作，我测试了，所有错误的通知问题都消失了:

  self.locationManager.distanceFilter =5.0;

您正在使用self.locationManager.distancefilter=0.0001，我认为CLLocationManager无法跟踪如此小的运动。此外，你还需要过滤掉旧的位置，如Apple位置感知指南中提到的缓存位置更新。我在我的代码中使用了这个条件来过滤所有超过5秒的事件。

- (void)locationManager:(CLLocationManager *)manager
 didUpdateLocations:(NSArray *)locations
{
   CLLocation *currentLocation=[locations lastObject];
   NSDate* eventDate = currentLocation.timestamp;
   NSTimeInterval howRecent = [eventDate timeIntervalSinceNow];
   if(abs(howRecent)<5.0 && self.currentLocation.horizontalAccuracy<=10 && self.currentLocation.horizontalAccuracy>0)
   {
     //you have got fresh location event here.
   }
}

Answer 2

我想用这个

让距离过滤器有效

self.locationManager.distanceFilter = kCLDistanceFilterNone;

你可以开始更新location方法也可以尝试这个方法这两个方法都需要得到确切的location

[locationManager startMonitoringSignificantLocationChanges];