getLastKnownLocations always returns null

问题

I am unable to getLastKnownLocations on my Android device (Samsung Galaxy Note N7000) as it is always null, towers is detected as network so it is fine, anybody got any idea how to get my location?

    d = getResources().getDrawable(R.drawable.songs_gray);

    //Placing pinpoint at location
    lm = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
    Criteria crit = new Criteria();

    towers = lm.getBestProvider(crit, false);

    Toast.makeText(LocationActivity.this, "Towers: " + towers, Toast.LENGTH_SHORT).show();

    Location location = lm.getLastKnownLocation(towers);

    Toast.makeText(LocationActivity.this, "Location: " + location, Toast.LENGTH_SHORT).show();

    if(location !=null){
        lat = (int) (location.getLatitude()*1E6);
        longi = (int) (location.getLongitude()*1E6);
        GeoPoint ourLocation = new GeoPoint(lat, longi);
        OverlayItem overlayItem = new OverlayItem(ourLocation, "What's up", "2nd String");
        CustomPinpoint custom = new CustomPinpoint(d, LocationActivity.this);
        custom.insertPinPoint(overlayItem);
        overlayList.add(custom);    
    }else{
        Toast.makeText(LocationActivity.this, "Couldn't get provider", Toast.LENGTH_SHORT).show();
    }

Manifest

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

回答1:

the last known location is only available if the location has been determined by another app prior to your call. start maps or some other app and let it get a location lock. then run your app.

if you really need location in your app, you need to fall back to some other method, because you cannot depend on there being a last known location.

as a side note, ACCESS_MOCK_LOCATION isn't required here. from the docs,

Allows an application to create mock location providers for testing

回答2:

With getLastKnownLocation() you can only get a Location object when the specified location provider is active.

The documentation says:

Returns a Location indicating the data from the last known location fix obtained from the given provider. This can be done without starting the provider. Note that this location could be out-of-date, for example if the device was turned off and moved to another location.

If the provider is currently disabled, null is returned.

To detect the current position and not the last detected one you need to enable the location provider(s). This tutorial should help you to understand how to work with location providers as GPS and network.

回答3:

Nevermind found out my problem! Just needed to on Google's Location Services on my phone

来源：https://stackoverflow.com/questions/11702848/getlastknownlocations-always-returns-null

标签

android

location