getLastKnownLocation（）始终返回null，所有提供者都是DummyLocationProvider

我看过很多关于这个问题的post，但没有一个为我提供解决方案。

我试图通过GPS（或最终，任何其他有效的提供商）获得用户位置。 但我总是得到零位置。 我确实得到了一张地图，并且可以设置一个任意位置，是不起作用的提供者。

我正确设置了我的MAPS键 （也检查了它是正确的），所有必要的权限设置（ android.permission.INTERNET ， android.permission.ACCESS_COARSE_LOCATION ， android.permission.ACCESS_FINE_LOCATION ），事实上，所有似乎都在工作昨天很好！

我尝试使用此代码获取所有可能的提供程序：

 List providers = locManager.getAllProviders(); for (String provider : providers) { printProvider(provider); } 

这显示了所有提供者（在我的情况下为4）是DummyLocationProviders。

我试图在手机上运行我的应用程序，而不是模拟器 （虽然我也尝试使用模拟器，启用GPS，但无济于事）。

这是我用来获取位置的代码（昨天工作得很好）：

 //Get criteria Criteria criteria = new Criteria(); criteria.setAccuracy(Criteria.ACCURACY_FINE); //Get best provider String bestProvider = locManager.getBestProvider(criteria, false); printProvider(bestProvider); //get the current location (last known location) from the location manager Location location = locManager.getLastKnownLocation(bestProvider); //if location found display as a toast the current latitude and longitude if (location != null) { Toast.makeText(this, "Current location:\nLatitude: " + location.getLatitude() + "\n" + "Longitude: " + location.getLongitude(), Toast.LENGTH_LONG).show(); point = new GeoPoint((int) (location.getLatitude()*1E6),(int)(location.getLongitude() *1E6)); controller.animateTo(point); } else { Toast.makeText(this, "Cannot fetch current location!", Toast.LENGTH_LONG).show(); } 

我的清单文件：

Answer 1

试试这段代码：

  import java.io.IOException; import java.util.List; import java.util.Locale; import android.content.Context; import android.graphics.Canvas; import android.location.Address; import android.location.Geocoder; import android.location.Location; import android.location.LocationListener; import android.location.LocationManager; import android.os.Bundle; import android.widget.Toast; import com.google.android.maps.GeoPoint; import com.google.android.maps.MapActivity; import com.google.android.maps.MapController; import com.google.android.maps.MapView; import com.google.android.maps.Overlay; public class MyMapsActivity extends MapActivity { MapView mapView; MapController mapController; LocationManager locationManager; LocationListener locationListener; /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); mapView = (MapView) findViewById(R.id.mapView); // enable Street view by default mapView.setStreetView(true); // enable to show Satellite view // mapView.setSatellite(true); // enable to show Traffic on map // mapView.setTraffic(true); mapView.setBuiltInZoomControls(true); mapController = mapView.getController(); mapController.setZoom(5); locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE); locationListener = new GPSLocationListener(); locationManager.requestLocationUpdates( LocationManager.GPS_PROVIDER, 0, 0, locationListener); Touchy t = new Touchy(); List overlayList = mapView.getOverlays(); overlayList.add(t); } @Override protected boolean isRouteDisplayed() { // TODO Auto-generated method stub return false; } class Touchy extends Overlay { public boolean onTap(GeoPoint point, MapView mapView) { Context contexto = mapView.getContext(); String msg = "Latitude : " + point.getLatitudeE6()/1E6 + " - " + "Longitude : " + point.getLongitudeE6()/1E6; Toast toast = Toast.makeText(contexto, msg, Toast.LENGTH_SHORT); toast.show(); return true; } } private class GPSLocationListener implements LocationListener { public void onLocationChanged(Location location) { if (location != null) { GeoPoint point = new GeoPoint((int) (location.getLatitude() * 1E6),(int) (location.getLongitude() * 1E6)); Toast.makeText(getBaseContext(),"Latitude: " + location.getLatitude() + " Longitude: " + location.getLongitude(), Toast.LENGTH_SHORT).show(); mapController.animateTo(point); mapController.setZoom(5); mapView.invalidate(); } if (location != null) { GeoPoint point=null; String address = ConvertPointToLocation(point); Toast.makeText(getBaseContext(), address, Toast.LENGTH_SHORT).show(); } } public String ConvertPointToLocation(GeoPoint point) { String address = ""; Geocoder geoCoder = new Geocoder(getBaseContext(), Locale.getDefault()); try { List
 addresses = geoCoder.getFromLocation(point.getLatitudeE6() / 1E6, point.getLongitudeE6() / 1E6, 1); if (addresses.size() > 0) { for (int index = 0; index < addresses.get(0).getMaxAddressLineIndex(); index++) address += addresses.get(0).getAddressLine(index) + " "; } } catch (IOException e) { e.printStackTrace(); } return address; } 

}

布局编码：

获取自己的API密钥流程的链接：

http://sanathnandasiri.blogspot.in/2011/04/obtaining-google-maps-api-key-for.html

Answer 2

//从位置管理器获取当前位置（最后一个已知位置）Location location = locManager.getLastKnownLocation（bestProvider）;

使用此而不是上面的行

  location = locManager.getLastKnownLocation(bestProvider); locManager.requestLocationUpdates(bestProvider,0, 0, locationListener); location = locManager.getLastKnownLocation(bestProvider); locManager.requestLocationUpdates(bestProvider,0, 0, locationListener); 

第一次位置为空，因此设置当前位置是最后一个位置。