Question

这是我的GPS代码。并返回（0,0）作为位置的latlng。如何在返回值不等于（0,0）之前等待几分钟。

这是我的代码：

public class Gps implements LocationListener {
    public static double lon;
    public static double lat;
    Location location;
    @Override
    public void onLocationChanged(Location location) {
        this.location=location;
        lon=location.getLongitude();
        lat=location.getLatitude();
      }
    @Override
    public void onStatusChanged(String provider, int status, Bundle extras) {
    }
    @Override
    public void onProviderEnabled(String provider) {
    }
    @Override
    public void onProviderDisabled(String provider) {
    }
}

和

 public String gps() {
        String str_gps=null;
        LocationManager lm = null;
        LocationListener ll = new Gps();
        lm = (LocationManager) getSystemService(G.context.LOCATION_SERVICE);

        if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
            return null;
        }
        boolean gpsEnabled = lm.isProviderEnabled(LocationManager.GPS_PROVIDER);
        if (!gpsEnabled) {
            Intent settingsIntent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
            startActivity(settingsIntent);
        }
        gpsEnabled = lm.isProviderEnabled(LocationManager.GPS_PROVIDER);
        lm.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, ll);
        str_gps = "(" + Gps.lat + "," + Gps.lon + ")";
        return str_gps;
    }

我正在考虑使用线程但不知道在哪里使用它。

Answer 1

此示例代码使用timer来检查gps的有效值。调用startRecording（）获取gps

private Location getBestLocation() {
    Location mainLocation = null;
    Location gpslocation = getLocationByProvider(LocationManager.GPS_PROVIDER);
    Location networkLocation =
            getLocationByProvider(LocationManager.NETWORK_PROVIDER);
    long old = System.currentTimeMillis() - checkInterval * 2;
    boolean gpsIsOld = true;
    boolean networkIsOld = true;


    // if we have only one location available, the choice is easy
    if (gpslocation == null) {
        Log.d("gps", "No GPS Location available.");
        return networkLocation;
    }
    if (networkLocation == null) {
        Log.d("gps", "No Network Location available");
        return gpslocation;
    }
    if (gpslocation.getTime() < old) {

        if (networkLocation.getTime() < old) {
            return null;
        }
        return networkLocation;
    }


    return gpslocation;
}



/**
 * get the last known location from a specific provider (network/gps)
 */
@SuppressWarnings({"ResourceType"})
private Location getLocationByProvider(String provider) {
    Location location = null;

    LocationManager locationManager = (LocationManager) getActivity().getApplicationContext()
            .getSystemService(Context.LOCATION_SERVICE);
    try {
        if (locationManager.isProviderEnabled(provider)) {
            location = locationManager.getLastKnownLocation(provider);
        }
    } catch (IllegalArgumentException e) {
        Log.d("gps", "Cannot acces Provider " + provider);
    }
    return location;
}

//noinspection ResourceType
@SuppressWarnings({"ResourceType"})
public void startRecording() {
    //gpsTimer.cancel();
    gpsTimer = new Timer();
    locationManager = (LocationManager) getActivity().getApplicationContext()
            .getSystemService(Context.LOCATION_SERVICE);
    for (String s : locationManager.getAllProviders()) {
        checkGps = false;
        //startRecording();
        locationManager.requestLocationUpdates(s, updateTime,
                minDistance, new LocationListener() {

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

                    @Override
                    public void onProviderEnabled(String provider) {
                    }

                    @Override
                    public void onProviderDisabled(String provider) {
                    }

                    @Override
                    public void onLocationChanged(Location location) {

                        doLocationUpdate(location, true);

                    }
                });
        gps_recorder_running = true;
    }

    /**
     if we want to access ui thread
     */


    // start the gps receiver thread
    timerTask = new TimerTask() {
        @Override
        public void run() {
            Location location = getBestLocation();
            if (location != null) {

                double latitude = location.getLatitude();
                double longtitude = location.getLongitude();
                SharedPreferencesTools.savelatitude(getContext(),
                        getString(R.string.constant_shared_latitude), "" + latitude);
                SharedPreferencesTools.saveLongtitude(getContext(),
                        getString(R.string.constant_shared_longtitude), "" + longtitude);
                Log.i("milliSeconds", "" + date);
                Log.i("location_shared", "" + location);
               // 

            } 
        }
    };

    gpsTimer.schedule(timerTask, checkInterval);
}

public void doLocationUpdate(Location l, boolean force) {
    Log.d("gps", "update received:" + l);
    myLocation = l;
    if (l == null) {
        Log.d("gps", "Empty location");
        if (force)
            Toast.makeText(getActivity(), "Current location not available",
                    Toast.LENGTH_SHORT).show();
        return;
    }
}

怎么说GPS等待几分钟直到返回不为零的位置

1 个答案: