java - Androidで緯度と経度を取得するにはどうすればよいですか？

Question

android2.3.3で現在の緯度と経度を取得するにはどうすればよいですか？

これをフォローしようとしましたが、プログラムを実行できません。

私のコード

    LatView = (TextView)findViewById(R.id.LatText);
    LngView = (TextView)findViewById(R.id.LngText);
    LocationManager lm = (LocationManager)getSystemService(Context.LOCATION_SERVICE); 
    Location location = lm.getLastKnownLocation(LocationManager.GPS_PROVIDER);
    double longitude = location.getLongitude();
    double latitude = location.getLatitude();

アンドロイドマニフェストにこれを入れました。

<uses-permission android:name="android.permission.INTERNET" /> 
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />

助けてください。ありがとう。

Answer 1

これは、デバイスの現在の場所を見つけるためにアプリケーションにあるもので、正常に動作します:

public class MyLocationActivity extends Activity implements LocationListener {
    private LocationManager mgr;
    private String best;
    public static double myLocationLatitude;
    public static double myLocationLongitude;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        mgr = (LocationManager) getSystemService(LOCATION_SERVICE);

        dumpProviders();

        Criteria criteria = new Criteria();

        best = mgr.getBestProvider(criteria, true);
        Log.d("best provider", best);

        Location location = mgr.getLastKnownLocation(best);
        dumpLocation(location);

            //may be some intent here
    }

    public void onLocationChanged(Location location) {
        // TODO Auto-generated method stub
        dumpLocation(location);

    }

    public void onProviderDisabled(String provider) {
        // TODO Auto-generated method stub

    }

    public void onProviderEnabled(String provider) {
        // TODO Auto-generated method stub

    }

    public void onStatusChanged(String provider, int status, Bundle extras) {
        // TODO Auto-generated method stub

    }

    @Override
    protected void onPause() {

        super.onPause();
        mgr.removeUpdates(this);
    }

    @Override
    protected void onResume() {

        super.onResume();
        mgr.requestLocationUpdates(best, 15000, 1, this);
    }

    private void dumpLocation(Location l) {

        if (l == null) {

            myLocationLatitude = 0.0;
            myLocationLongitude = 0.0;
        } else {

            myLocationLatitude = l.getLatitude();
            myLocationLongitude = l.getLongitude();
        }
    }

    private void dumpProviders() {

        List<String> providers = mgr.getAllProviders();
        for (String p : providers) {

            dumpProviders(p);
        }
    }

    private void dumpProviders(String s) {

        LocationProvider info = mgr.getProvider(s);
        StringBuilder builder = new StringBuilder();
        builder.append("name: ").append(info.getName());
    }

}

ここで MyLocationLatitude と MyLocationLongitude は、必要な緯度と経度の値を示します。

Answer 2

You need to check if the last location is null, if it is then you ask the GPS provider for a new location like so:

public class Example extends Activity implements LocationListener {
    LocationManager mLocationManager;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        mLocationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);

        Location location = mLocationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
        if(location != null && location.getTime() > Calendar.getInstance().getTimeInMillis() - 2 * 60 * 1000) {
            // Do something with the recent location if it is less than two minutes old
        }
        else {
            // Request a new location if necessary
            mLocationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, this);
        }
    }

    public void onLocationChanged(Location location) {
        if (location != null) {
        // Do something withthe current location

        // If you only want one location update un-comment this line
        //mLocationManager.removeUpdates(this);
        }
    }

    public void onProviderDisabled(String arg0) {}
    public void onProviderEnabled(String arg0) {}
    public void onStatusChanged(String arg0, int arg1, Bundle arg2) {}
}