iphone - CLLocationManager 跟踪错误位置 (Track Me)

Question

我在我的代码中实现了 Track me 选项。CLLocationManager 没有按预期工作。当我启动应用程序时，它保持在相同的位置，CLLocationManager 在 1 分钟内改变了大约 20-30 米..然后我保持不变。

如果我改变我的位置以跟踪同样的事情发生在开始 1 分钟 CLLocationManager 额外移动 20-30 分钟然后以我的速度移动..

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

我在当前的计步器应用程序中遇到了同样的问题。我伸了个懒腰，撞了我的头几天。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。所以我只是将 distancefilter 更改为 5.0 米，它开始工作得很好。尝试走 5 米它应该可以工作，我进行了测试，所有错误的通知问题都消失了:

  self.locationManager.distanceFilter =5.0;

您正在服用 self.locationManager.distancefilter=0.0001这是我认为 CLLocationManager 的容量不足跟踪这样一个小 Action 。您还需要过滤掉旧位置，即 Location Awareness Guide by Apple 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早于 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.
   }
}