Question

我正在尝试使用我在mainActivity中调用的服务来获取用户位置。我相信我已经完成了所有需要的工作，但问题是我每次回到经度为0，纬度为0！我也添加了用户权限，但它不起作用！这是服务类：

public class GPSTracker extends Service implements LocationListener{

private final Context context;

boolean isGPSEnabled = false;
boolean isNetworkEnabled = false;
boolean canGetLocation = false;

Location location;

double latitude;
double longitude;

private static final long MIN_DISTANCE_CHANGE_FOR_UPDATES = 10;
private static final long MIN_TIME_BW_UPDATES = 1000 * 60 * 1;

protected LocationManager locationManager;

public GPSTracker(Context context) {
    this.context = context;
    getLocation();
}

public Location getLocation() {
    try {
        locationManager = (LocationManager) context.getSystemService(LOCATION_SERVICE);

        isGPSEnabled = locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER);

        isNetworkEnabled = locationManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER);

        if(!isGPSEnabled && !isNetworkEnabled) {

        } else {
            this.canGetLocation = true;

            if (isNetworkEnabled) {

                locationManager.requestLocationUpdates(
                        LocationManager.NETWORK_PROVIDER,
                        MIN_TIME_BW_UPDATES,
                        MIN_DISTANCE_CHANGE_FOR_UPDATES, this);

                if (locationManager != null) {
                    location = locationManager
                            .getLastKnownLocation(LocationManager.NETWORK_PROVIDER);

                    if (location != null) {

                        latitude = location.getLatitude();
                        longitude = location.getLongitude();
                    }
                }

            }

            if(isGPSEnabled) {
                if(location == null) {
                    locationManager.requestLocationUpdates(
                            LocationManager.GPS_PROVIDER,
                            MIN_TIME_BW_UPDATES,
                            MIN_DISTANCE_CHANGE_FOR_UPDATES, this);

                    if(locationManager != null) {
                        location = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);

                        if(location != null) {
                            latitude = location.getLatitude();
                            longitude = location.getLongitude();
                        }
                    }
                }
            }
        }

    } catch (Exception e) {
        e.printStackTrace();
    }

    return location;
}


public void stopUsingGPS() {
    if(locationManager != null) {
        locationManager.removeUpdates(GPSTracker.this);
    }
}

public double getLatitude() {
    if(location != null) {
        latitude = location.getLatitude();
    }
    return latitude;
}

public double getLongitude() {
    if(location != null) {
        longitude = location.getLongitude();
    }

    return longitude;
}

public boolean canGetLocation() {
    return this.canGetLocation;
}

public void showSettingsAlert() {
    AlertDialog.Builder alertDialog = new AlertDialog.Builder(context);

    alertDialog.setTitle("GPS is settings");

    alertDialog.setMessage("GPS is not enabled. Do you want to go to settings menu?");

    alertDialog.setPositiveButton("Settings", new DialogInterface.OnClickListener() {

        @Override
        public void onClick(DialogInterface dialog, int which) {
            Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
            context.startActivity(intent);
        }
    });

    alertDialog.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {

        @Override
        public void onClick(DialogInterface dialog, int which) {
            dialog.cancel();
        }
    });

    alertDialog.show();
}

@Override
public void onLocationChanged(Location arg0) {
    // TODO Auto-generated method stub
    this.location = location;
    getLatitude();
    getLongitude();
}

@Override
public void onProviderDisabled(String arg0) {
    // TODO Auto-generated method stub

}

@Override
public void onProviderEnabled(String arg0) {
    // TODO Auto-generated method stub

}

@Override
public void onStatusChanged(String arg0, int arg1, Bundle arg2) {
    // TODO Auto-generated method stub

}

@Override
public IBinder onBind(Intent intent) {
    // TODO Auto-generated method stub
    return null;
}

}

这就是我在mainActivity中调用它的方式：

public class MainActivity extends Activity {

GPSTracker gps;



@Override
protected void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);

    gps = new GPSTracker(MainActivity.this);

    if (gps.canGetLocation()) {
        double latitude = gps.getLatitude();
        double longitude = gps.getLongitude();
        Log.v("Your LOCATION is -" + "Lat:", latitude + "Long: " + longitude  );
        Toast.makeText(
                getApplicationContext(),
                "Your LOCATION is -\nLat: " + latitude + "\nLong: "
                        + longitude, Toast.LENGTH_LONG).show();
    } else {
        gps.showSettingsAlert();
    }





}
}

欢迎所有建议

Answer 1

感谢Dainel，我发现它是如何工作的！对于遇到与我相同问题的人，只需使用此链接中的此代码即可使用Google Play服务 ACCESS_COARSE_LOCATION permission gives a cell tower precision on Android

并将其作为一项服务，只需使用main这样的意图：

Intent GPSt = new Intent(this, yourClassName.class);
        startService(GPSt);

Answer 2

嗯，说实话，我对GPSTracker不太熟悉，但我至少建议改变

public void onLocationChanged(Location arg0) {
    // TODO Auto-generated method stub
    this.location = location;
    getLatitude();
    getLongitude();
}

从我收集的内容来看，“arg0”是更新的位置，从未在方法中使用过。我建议将其改为。

 public void onLocationChanged(Location currentLocation) {
     this.location = currentLocation;
     getLatitude();
     getLongitude();
 }

Answer 3

我建议您尝试重构代码的GPS部分吗？有一个新的Location API比LocationManager更容易使用，并且没有充分的实现问题。

Fused Location Provider API管理围绕电池问题的电源管理等问题。一个很好的例子位于Github

Android GPS跟踪器每次返回0表示经度和纬度

3 个答案: