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我想连续跟踪用户位置作为android中的后台服务，我可以使用后台服务和广播接收器来实现它，但无法弄清楚如何根据可用性在网络和gps提供商之间切换。

背景服务.java 

 @Override

        public int onStartCommand(Intent intent, int flags, int startId) {
        mylistner = new NewLocationListener(getBaseContext());

        Criteria criteria = new Criteria();
        criteria.setAccuracy(Criteria.ACCURACY_FINE);
        criteria.setPowerRequirement(Criteria.POWER_LOW);

        criteria.setCostAllowed(true);
        LocationManager locManager = (LocationManager) getBaseContext()
        .getSystemService(Context.LOCATION_SERVICE);
        String bestProvider = locManager.getBestProvider(criteria, false);
            Toast.makeText(getBaseContext(), "Best Provider "+bestProvider, Toast.LENGTH_SHORT).show();
        locManager.requestLocationUpdates(bestProvider, 1000, 5, mylistner);
        Toast.makeText(getBaseContext(), "Successfully Called", Toast.LENGTH_SHORT).show();
        return START_STICKY;
    }

最初 bestProvider 将有 gps 或网络，但如果它最初是 gps，然后如果用户关闭 gps，它应该使用网络给我协调。同样，如果用户打开 gps，则位置提供者应该来自 gps。

在服务上有 onProviderEnabled 和 onProviderDisabled 方法如何使用它们

作为堆栈溢出中许多类似问题的解决方案，我不想从一开始就同时发送网络和 gps 提供商，我想根据可用性进行切换。在服务中是否可以实现。提前致谢

4

1 回答 1

0

这可以帮助您重新考虑问题：

public class GPSTracker extends Service implements android.location.LocationListener {
    /**
     * ¨PRIVATE ATTRIBUTES
     */
    // log
    private static final String TAG                             = GPSTracker.class.getSimpleName();
    //
    private Context             _context;
    private static GPSTracker   _instance;
    // The minimum distance to change Updates in meters
    private static final long   MIN_DISTANCE_CHANGE_FOR_UPDATES = 0;                                // meters
    // The minimum time between updates in milliseconds
    private static final long   MIN_TIME_BW_UPDATES             = 1000 * 30 * 1;                    // minute
    // Declaring a Location Manager
    protected LocationManager   _locationManager;
    /**
     * PUBLIC ATTRIBUTES
     */
    boolean                     _isGPSEnabled                   = false;
    boolean                     _isNetworkEnabled               = false;
    boolean                     _canGetLocation                 = false;
    public Location             _location;
    double                      _latitude;
    double                      _longitude;

    public GPSTracker() {

        _context = null;
    }

    public static GPSTracker getInstance() {

        if (_instance == null) {
            _instance = new GPSTracker();
        }
        return _instance;
    }

    public void set_context(Context context) {

        this._context = context;
    }

    public Location getLocation(Context context) {

        _context = context;
        try {
            _locationManager = (LocationManager) _context.getSystemService(LOCATION_SERVICE);
            _isGPSEnabled = _locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER);
            _isNetworkEnabled = _locationManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER);
            if (!_isGPSEnabled && !_isNetworkEnabled) {
                // no network provider is enabled
            }
            else {
                this._canGetLocation = true;
                if (_isNetworkEnabled) {
                    _locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, MIN_TIME_BW_UPDATES, MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
                    Log.d("Network", "Network");
                    if (_locationManager != 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) {
                        _locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, MIN_TIME_BW_UPDATES, MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
                        Log.d("GPS Enabled", "GPS Enabled");
                        if (_locationManager != null) {
                            _location = _locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
                            if (_location != null) {
                                _latitude = _location.getLatitude();
                                _longitude = _location.getLongitude();
                            }
                        }
                    }
                }
            }
        }
        catch (Exception e) {
            // TODO: ERROR getLocation
        }
        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;
    }

    /**
     * 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 lauch Settings Options
     */
    public void showSettingsAlert(String title, String msg) {

        AlertDialog.Builder alertDialog = new AlertDialog.Builder(_context);
        alertDialog.setTitle(title);
        alertDialog.setMessage(msg);
        // Settings button
        alertDialog.setPositiveButton("Paramètres", new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog, int which) {

                Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
                _context.startActivity(intent);
            }
        });
        // cancel button
        alertDialog.setNegativeButton("Annuler", new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog, int which) {

                dialog.cancel();
            }
        });
        // show
        alertDialog.show();
    }

    @Override
    public void onLocationChanged(Location location) {

        Log.i(TAG, "onLocationChanged--TRACKER--" + location.getLatitude() + " / " + location.getLongitude());
    }

    @Override
    public void onProviderDisabled(String provider) {

    }

    @Override
    public void onProviderEnabled(String provider) {

    }

    @Override
    public void onStatusChanged(String provider, int status, Bundle extras) {

    }

    @Override
    public IBinder onBind(Intent arg0) {

        return null;
    }
}
于 2013-08-23T08:12:57.653 回答