使用 Google API 的 Android 融合位置

Question

我是一名初级 Android 开发人员。我正在使用 Android Studio 构建一个应用程序，它可以为您提供确切的位置并在每个时间段不断更新它。我通过创建一个 GPStracker 类来使用 GPS 和网络提供商，该类为我提供纬度和经度。然后在 map fragment 上显示这些坐标。

问题是我一次又一次地获得相同的位置，对应的经度和纬度等于零。我知道有很多关于 Android 位置的问题，但我在那里找不到帮助。

这是我更新 map 的地方

 private void updateMap() {
    mMap.clear();
    double latitude = gps.getLatitude();
    double longitude = gps.getLongitude();

    // Create a LatLng object for the current location
    LatLng latLng = new LatLng(latitude, longitude);
    // Show the current location in Google Map
    mMap.moveCamera(CameraUpdateFactory.newLatLng(latLng));
    // Zoom in the Google Map
    mMap.animateCamera(CameraUpdateFactory.zoomTo(1));
    mMap.addMarker(new MarkerOptions().position(new LatLng(latitude, longitude)).title("You are here!").snippet("Estimated location!"));
    //camera settings
    CameraUpdate yourLocation = CameraUpdateFactory.newLatLngZoom(latLng, 1);
    mMap.animateCamera(yourLocation);
    CameraPosition cameraPosition = new CameraPosition.Builder()
            .target(latLng)      // Sets the center of the map to LatLng (refer to previous snippet)
            .zoom(1)                   // Sets the zoom
            .bearing(90)                // Sets the orientation of the camera to east
            .tilt(30)                   // Sets the tilt of the camera to 30 degrees
            .build();                   // Creates a CameraPosition from the builder
    mMap.animateCamera(CameraUpdateFactory.newCameraPosition(cameraPosition));
}

这是我的 GPStracker 类(class)

public abstract class GPSTracker extends Service implements LocationListener {
private final Context mContext;
// flag for GPS status
boolean isGPSEnabled = false;
// flag for network status
boolean isNetworkEnabled = false;
// flag for GPS status
boolean canGetLocation = false;
Location location; // location
double latitude; // latitude
double longitude; // longitude
double speed, direction;
// The minimum distance to change Updates in meters
private static final long MIN_DISTANCE_CHANGE_FOR_UPDATES = 10; // 10 meters
// The minimum time between updates in milliseconds
private static final long MIN_TIME_BW_UPDATES = 1000 * 60 * 1; // 1 minute
// Declaring a Location Manager
protected LocationManager locationManager;

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

public Location getLocation() {
    try {
        locationManager = (LocationManager) mContext
                .getSystemService(LOCATION_SERVICE);
        // getting GPS status
        isGPSEnabled = locationManager
                .isProviderEnabled(LocationManager.GPS_PROVIDER);
        // getting network status
        isNetworkEnabled = locationManager
                .isProviderEnabled(LocationManager.NETWORK_PROVIDER);
        if (!isGPSEnabled && !isNetworkEnabled) {
            Toast.makeText(this, "no network provider is enabled)",
                    Toast.LENGTH_LONG).show();
            showSettingsAlert();
            // no network provider is enabled
        } else {
            this.canGetLocation = true;
            // First get location from Network Provider
            if (isNetworkEnabled) {
                Toast.makeText(this, "Network provider)",
                        Toast.LENGTH_LONG).show();
                locationManager.requestLocationUpdates(
                        LocationManager.NETWORK_PROVIDER,
                        MIN_TIME_BW_UPDATES,
                        MIN_DISTANCE_CHANGE_FOR_UPDATES, (android.location.LocationListener) this);
                Log.d("Network", "Network");
                if (locationManager != null) {
                    if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
                        // TODO: Consider calling
                        //    ActivityCompat#requestPermissions
                        // here to request the missing permissions, and then overriding
                        //   public void onRequestPermissionsResult(int requestCode, String[] permissions,
                        //                                          int[] grantResults)
                        // to handle the case where the user grants the permission. See the documentation
                        // for ActivityCompat#requestPermissions for more details.
                        return null;
                    }
                    location = locationManager
                            .getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
                    if (location != null) {
                        latitude = location.getLatitude();
                        longitude = location.getLongitude();
                    }
                }
            }
            // if GPS Enabled get lat/long using GPS Services
            if (isGPSEnabled) {
                if (location == null) {
                    Toast.makeText(this, "GPS provider)",
                            Toast.LENGTH_LONG).show();
                    locationManager.requestLocationUpdates(
                            LocationManager.GPS_PROVIDER,
                            MIN_TIME_BW_UPDATES,
                            MIN_DISTANCE_CHANGE_FOR_UPDATES, (android.location.LocationListener) this);
                    Log.d("GPS Enabled", "GPS Enabled");
                    if (locationManager != null) {
                        Log.d("Getting location", "Location found");
                        location = locationManager
                                .getLastKnownLocation(LocationManager.GPS_PROVIDER);
                        if (location != null) {
                            latitude = location.getLatitude();
                            longitude = location.getLongitude();
                        }
                    }
                }
            }
        }
    } catch (Exception e) {
        e.printStackTrace();
    }
    return location;
}

/**
 * Stop using GPS listener
 * Calling this function will stop using GPS in your app
 * */
public void stopUsingGPS() {
    if (locationManager != null) {
        if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
            // TODO: Consider calling
            //    ActivityCompat#requestPermissions
            // here to request the missing permissions, and then overriding
            //   public void onRequestPermissionsResult(int requestCode, String[] permissions,
            //                                          int[] grantResults)
            // to handle the case where the user grants the permission. See the documentation
            // for ActivityCompat#requestPermissions for more details.
            return;
        }
        locationManager.removeUpdates((android.location.LocationListener) GPSTracker.this);
    }
}
/**
 * Function to get latitude
 * */
public double getLatitude(){
    if(location != null){
        latitude = location.getLatitude();
    }
    // return latitude
    return latitude;
}
/**
 * Function to get longitude
 * */
public double getLongitude(){
    if(location != null){
        longitude = location.getLongitude();
    }
    // return longitude
    return longitude;
}
public double getSpeed(){
    return speed;
}
public double getDirection(){
    return direction;
}
/**
 * Function to check GPS/wifi enabled
 * @return boolean
 * */
public boolean canGetLocation() {
    return this.canGetLocation;
}
/**
 * Function to show settings alert dialog
 * On pressing Settings button will launch Settings Options
 * */
public void showSettingsAlert(){
    AlertDialog.Builder alertDialog = new AlertDialog.Builder(mContext);
    // Setting Dialog Title
    alertDialog.setTitle("GPS is settings");
    // Setting Dialog Message
    alertDialog.setMessage("GPS is not enabled. Do you want to go to settings menu?");
    // On pressing Settings button
    alertDialog.setPositiveButton("Settings", new DialogInterface.OnClickListener() {
        public void onClick(DialogInterface dialog,int which) {
            Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
            mContext.startActivity(intent);
        }
    });
    // on pressing cancel button
    alertDialog.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
        public void onClick(DialogInterface dialog, int which) {
            dialog.cancel();
        }
    });
    // Showing Alert Message
    alertDialog.show();
}
@Override
public void onLocationChanged(Location location) {
    if(location != null){
        speed = location.getSpeed();
        direction = location.getBearing();
    }
}

Answer 1

尝试使用 Android 模拟器或 genymotion 模拟器。它们具有向模拟器注入(inject)位置的出色功能。

此链接可帮助您启用 genymotion 的 GPS

https://docs.genymotion.com/Content/03_Virtual_Devices/Emulating_sensors_and_features/GPS.htm

以及此链接以在 Android 模拟器上启用 GPS

http://imgur.com/a/8ifzd