Xcode 4.5中的当前位置错误 [英] Current Location Bug in Xcode 4.5

问题描述

苹果在Xcode 4.5中引入了苹果新地图。我的应用比较重，需要地图服务。而且我注意到我的应用程序显示错误的当前位置，直到您删除该应用程序并重新打开它显示正确的当前位置（有时它不）。只要提到我连接到4G，当它显示错误的当前位置。有没有办法解决这个bug，因为我的应用程序需要正确的位置。提前致谢。如果你可以提供代码，这将有助于很多... 编辑： Apple Map App中的相同问题

我的代码： / strong>

   - （void）locationManager：（CLLocationManager *）manager 
 didUpdateToLocation：（CLLocation *）newLocation 
 fromLocation：（CLLocation *）oldLocation {
 {
 
} 
 
 if（！oldLocation）
 totalDistance = 0.0; 
 else 
 totalDistance + = [newLocation distanceFromLocation：oldLocation]; 
 
} 
  

解决方案

苹果文档的方法似乎仍然在iOS6中运行（没有注意到这在我的活动应用程序（它通过gps跟踪用户的路线））

 <$ c $ （CLLocation *）newLocation fromLocation：（CLLocation *）oldLocation {
 
 NSTimeInterval locationAge =  -  [newLocation.timestamp timeIntervalSinceNow];（c） - （void）locationManager：（CLLocationManager *）manager didUpdateToLocation 
 if（locationAge> 5.0）return; 
 if（newLocation.horizo​​ntalAccuracy< 0）return; 
 
 //在这里继续进行协调
} 
  

更新：
可以像这样计算总计和当前距离（不包括一些小的东西）：

  //某处顶部
 CLLocation * lastUsedLocation = nil; //最后一个位置用于计算
 CLLocation * pointA = nil; //开始轨道
 double totalDistance = 0; //轨道总距离
 double currentDistance = 0; // startTrack点和当前位置之间的距离
 ... 
 
 //当您开始更新位置时：
  - （void）startTracking {
 lastUsedLocation = nil; 
 pointA = nil; 
 totalDistance = 0; 
 currentDistance = 0; 
 [locationManager startUpdatingLocation]; 
} 
 ... 
 
 
 //位置更新回调
  - （void）locationManager：（CLLocationManager *）manager didUpdateToLocation：（CLLocation *） newLocation fromLocation：（CLLocation *）oldLocation {
 NSTimeInterval locationAge =  -  [newLocation.timestamp timeIntervalSinceNow]; 
 if（locationAge> 5.0）return; // filter cached 
 if（newLocation.horizo​​ntalAccuracy< 0）return; // filter invalid 
 
 if（！pointA）pointA = [newLocation retain]; 
 
 if（lastUsedLocation）
 {
 totalDistance + = [newLocation distanceFromLocation：lastUsedLocation]; 
} 
 currentDistance = [pointA distanceFromLocation：newLocation]; 
 [lastUsedLocation release]; 
 lastUsedLocation = [newLocation retain]; 
} 
  

如果您需要选项关闭背景位置，请手动禁用如：

   - （void）applicationDidEnterBackground：（UIApplication *）应用程序{
 if（backgroundLocationDisabled）
 {
 [locationManager stopUpdatingLocation]; 
 //附加东西
} 
} 
  

In Xcode 4.5 apple introduced apple new maps. My application heavliy requires map services. And I have noticed in my application it shows the wrong current location until you delete the app and reopen it shows the right current location (Sometimes it doesn't). Just to mention I was connected to 4G when it show the wrong current location. Is there a way to fix this bug because my application heavily needs the right location. Thanks in advance. If you could provide code it would help a lot...Edit: Same Issue in Apple Map App

My Code:

- (void)locationManager:(CLLocationManager *)manager
    didUpdateToLocation:(CLLocation *)newLocation
           fromLocation:(CLLocation *)oldLocation {
    {

    }

    if (!oldLocation)
        totalDistance = 0.0;
    else
        totalDistance += [newLocation distanceFromLocation:oldLocation];

}

解决方案

The old approach from apple docs seems still working in iOS6 (didn't notice this in my active app (it tracks user's route via gps))

- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation {

    NSTimeInterval locationAge = -[newLocation.timestamp timeIntervalSinceNow];
    if (locationAge > 5.0) return;
    if (newLocation.horizontalAccuracy < 0) return; 

    // proceed with coords here
}

UPDATE from the discussion: Calculating total and current distance could be done like this (excluding some minor stuff):

// somewhere at the top
CLLocation* lastUsedLocation = nil; // last location used in calculation
CLLocation* pointA = nil;  // start of the track
double totalDistance = 0;  // total distance of track
double currentDistance = 0; // distance between startTrack point and current location
...

// when you start updating location:
- (void) startTracking {
    lastUsedLocation = nil;
    pointA = nil;
    totalDistance = 0;
    currentDistance = 0;
    [locationManager startUpdatingLocation];
}
...


// location update callback
 - (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation { 
    NSTimeInterval locationAge = -[newLocation.timestamp timeIntervalSinceNow]; 
    if (locationAge > 5.0) return;  // filter cached
    if (newLocation.horizontalAccuracy < 0) return; // filter invalid

    if(!pointA) pointA = [newLocation retain]; 

    if(lastUsedLocation) 
    { 
        totalDistance += [newLocation distanceFromLocation:lastUsedLocation]; 
    } 
    currentDistance = [pointA distanceFromLocation:newLocation]; 
    [lastUsedLocation release]; 
    lastUsedLocation = [newLocation retain]; 
}

If you need the option to turn off background location on purpose you disable it manually like:

- (void)applicationDidEnterBackground:(UIApplication *)application {
    if(backgroundLocationDisabled)
    {
        [locationManager stopUpdatingLocation];
        // additional stuff
    }
}

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