Question

我想在Android应用程序中找到我当前位置的纬度和经度。当我用手机稳定时，我只需要它。

我的代码是：

LocationManager locationManager;
    locationManager = (LocationManager)getSystemService
    (Context.LOCATION_SERVICE);
    Location location = locationManager.getLastKnownLocation
    (LocationManager.GPS_PROVIDER);


    locationManager.requestLocationUpdates(                
             LocationManager.GPS_PROVIDER,0,0,(LocationListener) this);
    updateWithNewLocation(location);
    }

    private void updateWithNewLocation(Location location) {
    TextView myLocationText = (TextView)findViewById(R.id.myLocationText);

    String latLongString;

    if (location != null) {
    double lat = location.getLatitude();
    double lng = location.getLongitude();
    latLongString = "Lat:" + lat + "\nLong:" + lng;
    } else {
    latLongString = "No location found";
    }

    myLocationText.setText("Your Current Position is:\n" +
    latLongString);
    }

在模拟器上运行后，我总是找到“找不到位置”。为什么会这样？

Answer 1

public class GPSmap extends Activity {

    GeoPoint geoPoint;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        LocationManager locManager;
        setContentView(R.layout.main);
        locManager =(LocationManager)getSystemService(Context.LOCATION_SERVICE);
        locManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 1000L,
            500.0f, locationListener);
        Location location = locManager
                .getLastKnownLocation(LocationManager.GPS_PROVIDER);
        if (location != null) {
            double latitude = location.getLatitude();
            double longitude = location.getLongitude();
        }
    }

    private void updateWithNewLocation(Location location) {
        TextView myLocationText = (TextView) findViewById(R.id.text);
        String latLongString = "";
        if (location != null) {
            double lat = location.getLatitude();
            double lng = location.getLongitude();
            latLongString = "Lat:" + lat + "\nLong:" + lng;
        } else {
            latLongString = "No location found";
        }
        myLocationText.setText("Your Current Position is:\n" + latLongString);
    }

    private final LocationListener locationListener = new LocationListener() {

        public void onLocationChanged(Location location) {
            updateWithNewLocation(location);
        }

        public void onProviderDisabled(String provider) {
            updateWithNewLocation(null);
        }

        public void onProviderEnabled(String provider) {}

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

如果您将使用此代码，您将得到答案。

Answer 2

GPS收音机并非一直处于打开状态，因为它会严重耗尽电池电量。在您拨打getLastKnownLocation()时，收音机可能已关闭。

您需要先执行requestLocationUpdates()，然后等待修复程序提供给LocationListener。在此之后的任何时间（removeUpdates()），getLastKnownLocation()都应返回非null值。

Answer 3

我有很多教程，但发现了最好的教程：

使用Criteria和BestProvider

    /** PROCESS for Get Longitude and Latitude **/
locationManager = (LocationManager) getActivity().getSystemService(Context.LOCATION_SERVICE);

// getting GPS status
isGPSEnabled = locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER);
Log.d("msg", "GPS:"+isGPSEnabled);

// check if GPS enabled     
if(isGPSEnabled){
    /*
    longitude = 70.80079728674089;
    latitude =  22.29090332494221;
     */
     Criteria criteria = new Criteria();
     String provider = locationManager.getBestProvider(criteria, false);
     Location location = locationManager.getLastKnownLocation(provider);

    //new LoadPlaces().execute();
    //Location location = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
    if(location != null)
    {
        longitude = location.getLongitude();
        latitude = location.getLatitude();
        Log.d("msg", "first lat long : "+latitude +" "+ longitude);
        //new LoadPlaces().execute();
    }else
    {
        locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, new LocationListener() {

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

            }

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

            }

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

            }

            @Override
            public void onLocationChanged(Location location) {
                // TODO Auto-generated method stub
                longitude = location.getLongitude();
                latitude = location.getLatitude();
                Log.d("msg", "changed lat long : "+latitude +" "+ longitude);
            }
        });
    }

}
else
{
    showAlertforGPS();
}

Answer 4

默认情况下，模拟器可能没有任何关联的位置。所以它没有给予任何。

要发送位置，请转到Eclipse中的DDMS透视图，然后输入纬度和经度并单击“发送”。然后，您将能够在您的应用程序中看到它。

如果您还有任何问题，请与我们联系。

在Android中查找当前位置的经度和纬度

4 个答案: