在我的应用程序中，我需要实现实时位置跟踪并找到人行进的总距离。我尝试过使用Google位置管理器API。我可以在旅行时从设备成功获取位置。但是源和目的地之间的距离是错误的。它似乎不准确。这是我的后台服务的代码，用于获取位置和计算距离。
public class MyService extends Service {
private static final String TAG = "gpstest";
private static final int LOCATION_INTERVAL = 3000;
private static final float LOCATION_DISTANCE = 5;
LocationListener[] mLocationListeners = new LocationListener[]{
new LocationListener(LocationManager.GPS_PROVIDER),
new LocationListener(LocationManager.NETWORK_PROVIDER),
};
Location mLastLocation;
private LocationManager mLocationManager = null;
private double lat;
private double log;
private RetrofitClient.APIServiceGetDistanceMap apiServiceGetDistanceMap;
private RetrofitClient.MakeMyTrip makeMyTrip;
private String id;
private String t_id;
private boolean isStop = false;
private double srclat;
private double srclog;
private double destlat;
private double destlog;
private double total;
@Override
public IBinder onBind(Intent arg0) {
return null;
}
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
Log.e(TAG, "onStartCommand");
lat = intent.getDoubleExtra("lat", 0);
log = intent.getDoubleExtra("log", 0);
if (mLastLocation != null) {
mLastLocation.setLatitude(0);
mLastLocation.setLongitude(0);
}
super.onStartCommand(intent, flags, startId);
return START_STICKY;
}
@Override
public void onCreate() {
Log.e(TAG, "onCreate");
PowerManager pm = (PowerManager) getApplicationContext().getSystemService(Context.POWER_SERVICE);
PowerManager.WakeLock wl = pm.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, "TAG");
wl.acquire(720000000);
WifiManager wm = (WifiManager) getApplicationContext().getApplicationContext().getSystemService(Context.WIFI_SERVICE);
WifiManager.WifiLock wifiLock = wm.createWifiLock(WifiManager.WIFI_MODE_FULL, "TAG");
wifiLock.acquire();
SharedPreferences sharedPref = getApplicationContext().getSharedPreferences("my", Context.MODE_PRIVATE);
String username = sharedPref.getString("user_name", null);
id = String.valueOf(sharedPref.getInt("id", 0));
t_id = sharedPref.getString("t_id", "");
initializeLocationManager();
apiServiceGetDistanceMap = RetrofitClient.getDistanceMap(Constants.MAP_URL);
makeMyTrip = RetrofitClient.makeTrip(Constants.BASE_URL);
try {
mLocationManager.requestLocationUpdates(
LocationManager.NETWORK_PROVIDER, LOCATION_INTERVAL, LOCATION_DISTANCE,
mLocationListeners[1]);
} catch (java.lang.SecurityException ex) {
Log.i(TAG, "fail to request location update, ignore", ex);
} catch (IllegalArgumentException ex) {
Log.d(TAG, "network provider does not exist, " + ex.getMessage());
}
try {
mLocationManager.requestLocationUpdates(
LocationManager.GPS_PROVIDER, LOCATION_INTERVAL, LOCATION_DISTANCE,
mLocationListeners[0]);
} catch (java.lang.SecurityException ex) {
Log.i(TAG, "fail to request location update, ignore", ex);
} catch (IllegalArgumentException ex) {
Log.d(TAG, "gps provider does not exist " + ex.getMessage());
}
}
@Override
public void onDestroy() {
Log.e(TAG, "onDestroy");
super.onDestroy();
if (mLocationManager != null) {
for (int i = 0; i < mLocationListeners.length; i++) {
try {
mLocationManager.removeUpdates(mLocationListeners[i]);
} catch (Exception ex) {
Log.i(TAG, "fail to remove location listners, ignore", ex);
}
}
}
}
private void initializeLocationManager() {
Log.e(TAG, "initializeLocationManager");
if (mLocationManager == null) {
mLocationManager = (LocationManager) getApplicationContext().getSystemService(Context.LOCATION_SERVICE);
}
}
protected boolean isBetterLocation(Location location, Location currentBestLocation) {
if (currentBestLocation == null) {
// A new location is always better than no location
return true;
}
// Check whether the new location fix is newer or older
long timeDelta = location.getTime() - currentBestLocation.getTime();
boolean isSignificantlyNewer = timeDelta > LOCATION_INTERVAL;
boolean isSignificantlyOlder = timeDelta < -LOCATION_INTERVAL;
boolean isNewer = timeDelta > 0;
// If it's been more than two minutes since the current location, use the new location
// because the user has likely moved
if (isSignificantlyNewer) {
return true;
// If the new location is more than two minutes older, it must be worse
} else if (isSignificantlyOlder) {
return false;
}
// Check whether the new location fix is more or less accurate
int accuracyDelta = (int) (location.getAccuracy() - currentBestLocation.getAccuracy());
boolean isLessAccurate = accuracyDelta > 0;
boolean isMoreAccurate = accuracyDelta < 0;
boolean isSignificantlyLessAccurate = accuracyDelta > 10;
// Check if the old and new location are from the same provider
boolean isFromSameProvider = isSameProvider(location.getProvider(),
currentBestLocation.getProvider());
// Determine location quality using a combination of timeliness and accuracy
if (isMoreAccurate) {
return true;
} else if (isNewer && !isLessAccurate) {
return true;
} else if (isNewer && !isSignificantlyLessAccurate && isFromSameProvider) {
return true;
}
return false;
}
/**
* Checks whether two providers are the same
*/
private boolean isSameProvider(String provider1, String provider2) {
if (provider1 == null) {
return provider2 == null;
}
return provider1.equals(provider2);
}
private class LocationListener implements android.location.LocationListener {
public LocationListener(String provider) {
Log.e(TAG, "LocationListener " + provider);
mLastLocation = new Location(provider);
// mLastLocation.setLatitude(lat);
// mLastLocation.setLongitude(log);
}
@Override
public void onLocationChanged(final Location location) {
Log.e(TAG, "onLocationChanged: " + location);
if (mLastLocation != null) {
String source = String.valueOf(mLastLocation.getLatitude()).concat(",").concat(String.valueOf(mLastLocation.getLongitude()));
String destination = String.valueOf(String.valueOf(location.getLatitude())).concat(",").concat(String.valueOf(location.getLongitude()));
apiServiceGetDistanceMap.getMapDate(source, destination, "driving").enqueue(new Callback<MapData>() {
@Override
public void onResponse(Call<MapData> call, Response<MapData> response) {
ArrayList<Row> rowArrayList = new ArrayList<Row>();
if (response.isSuccessful()) {
rowArrayList = (ArrayList<Row>) response.body().getRows();
double distance = 0;
if (rowArrayList.size() > 0) {
for (int i = 0; i < rowArrayList.size(); i++) {
for (int j = 0; j < rowArrayList.get(i).getElements().size(); j++) {
if (rowArrayList.get(i).getElements().get(j).getDistance() != null) {
distance = distance + rowArrayList.get(i).getElements().get(j).getDistance().getValue();
}
}
}
Log.e("source..lat", "" + mLastLocation.getLatitude());
Log.e("source..log", "" + mLastLocation.getLongitude());
Log.e("destination..lat", "" + location.getLatitude());
Log.e("destination..log", "" + location.getLongitude());
Log.e("distance:", "" + distance / 1000);
final double dist = distance / 1000;
//call service to send location
srclat = mLastLocation.getLatitude();
srclog = mLastLocation.getLongitude();
destlat = mLastLocation.getLatitude();
destlog = mLastLocation.getLongitude();
total = dist;
Travel travel = new Travel();
travel.setId(id);
travel.setTid(t_id);
travel.setSrcLat(String.valueOf(mLastLocation.getLatitude()));
travel.setSrcLog(String.valueOf(mLastLocation.getLongitude()));
travel.setDestLat(String.valueOf(location.getLatitude()));
travel.setDestLog(String.valueOf(location.getLongitude()));
travel.setDist(String.valueOf(dist));
// check for accuracy of location
Log.e("meter", String.valueOf(distance));
double speed = distance / (location.getTime() - mLastLocation.getTime());
if (isBetterLocation(location, mLastLocation) && speed > 3 && distance < 300) {
if (mLastLocation.getLatitude() != 0 && mLastLocation.getLongitude() != 0 && location.getLatitude() != 0 && location.getLongitude() != 0) {
if (mLastLocation.getLatitude() != location.getLatitude() && mLastLocation.getLongitude() != location.getLongitude()) {
makeMyTrip.makeTrip(id, t_id, String.valueOf(mLastLocation.getLatitude()), String.valueOf(mLastLocation.getLongitude()),
String.valueOf(location.getLatitude()), String.valueOf(location.getLongitude()), String.valueOf(dist)).enqueue(new Callback<MyRes>() {
@Override
public void onResponse(Call<MyRes> call, Response<MyRes> response) {
}
@Override
public void onFailure(Call<MyRes> call, Throwable t) {
}
});
}
}
}
mLastLocation.set(location);
}
}
}
@Override
public void onFailure(Call<MapData> call, Throwable t) {
mLastLocation.set(location);
}
});
}
}
@Override
public void onProviderDisabled(String provider) {
Log.e(TAG, "onProviderDisabled: " + provider);
}
@Override
public void onProviderEnabled(String provider) {
Log.e(TAG, "onProviderEnabled: " + provider);
}
@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
Log.e(TAG, "onStatusChanged: " + provider);
}
}
}
答案 0 :(得分：1)
你必须使用这个公式逐步取两个lat lon之间的距离表示之前的lat lon和new lat lon。在添加所有距离给你准确的距离。如果您需要更高的精确度，还可以添加时间和速度因子。
public static float getDistanceInMiles(double currentLatitude, double currentLongitude, double newLatitude, double newLongitude) {
double latitude = newLatitude;
double longitude = newLongitude;
float distance = 0;
Location crntLocation = new Location("crntlocation");
crntLocation.setLatitude(currentLatitude);
crntLocation.setLongitude(currentLongitude);
Location newLocation = new Location("newlocation");
newLocation.setLatitude(latitude);
newLocation.setLongitude(longitude);
distance = crntLocation.distanceTo(newLocation);
//distance =crntLocation.distanceTo(newLocation) / 1000; // in km
return distance;
}