Apple ドキュメントの古いアプローチは、iOS6 でもまだ機能しているようです (アクティブなアプリではこれに気づきませんでした (GPS 経由でユーザーのルートを追跡します))。
- (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
}
ディスカッションからの更新:合計距離と現在の距離の計算は、次のように行うことができます (いくつかのマイナーなものを除く):
// 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];
}
意図的にバックグラウンドの位置情報をオフにするオプションが必要な場合は、次のように手動で無効にします。
- (void)applicationDidEnterBackground:(UIApplication *)application {
if(backgroundLocationDisabled)
{
[locationManager stopUpdatingLocation];
// additional stuff
}
}