NETWORK_PROVIDER在android中不起作用

Question

I build app for User to get last location or current location. I use both NETWORK_PROVIDER and GPS_PROVIDER .I have little problem with NETWORK_PROVIDER .

1.When i use NEWTWORK_PROVIDER in Micromax unit 2 than the app crash and when I use GPS_PROVIDER than app is working good. And same Application is working fine in Samsung and XIOMI devices while using both providers. Any Reason behind this?

2. Is NETWORK_PROVIDER supported for only limited version?

3. If some device doesn't support NETWORK_PROVIDER than what can i do to get current location without GPS?

Here's my code:

    private void beginAcquiringLocation() {

    //Log.d(TAG, "Beginning location acquisition");
    logStatus("Requesting location update.");

    // we don't want to be killed while handling data transmission in another thread
    // to guarantee we don't take an eternal lock even in case of bugs, set a timeout
    acquireWakeLock(WAKELOCK_TIME_DEFAULT);

    LocationManager locationManager =(LocationManager) this.getSystemService(Context.LOCATION_SERVICE);
    Criteria crit = new Criteria();
    String provider = locationManager.getBestProvider(crit, false);
    Location location = locationManager.getLastKnownLocation(provider);

    Log.d("LOCATION>>>>>>>>>>>", String.valueOf(location));

    Log.d("Provider---------->>>>>>>>", provider);
     // no significant time or distance minima, we'll decide if it's usable when we get a coord
    locationManager.requestLocationUpdates(provider, 500, 0, this);

    if(String.valueOf(location).equals("null")){

        locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 500, 0, this);
        Location l=locationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
        Log.d("-------Location default----->>>>>>>", String.valueOf(l));


    }
    // next action in process is in the callback upon receiving a location update

    // to prevent endless listening if no updates are ever received, we need to schedule a timeout
    timeoutHandler.removeCallbacks(timeoutTask);
    timeoutHandler.postDelayed(timeoutTask, timeoutDelay);
}

Answer 1

1. Micromax Unit 2 has a A-GPS, so it's strange if the app crashs: have you got more logs about this?
2. For me, there are 3 cases:

1. gps –> (GPS, AGPS) Requires the permission android.permission.ACCESS_FINE_LOCATION.
2. network –> (AGPS, CellID, WiFi MACID) Requires either of the permissions android.permission.ACCESS_COARSE_LOCATION or android.permission.ACCESS_FINE_LOCATION.
3. passive –> (CellID, WiFi MACID) Requires the permission android.permission.ACCESS_FINE_LOCATION, although if the GPS is not enabled this provider might only return coarse fixes.

If you need more informations, you can refer to: http://developerlife.com/tutorials/?p=1375

Answer 2

You can get Gps or Network provider is available or not by below code.

mLocationManager = (LocationManager) context.getSystemService(LOCATION_SERVICE);
boolean isGPSEnabled = mLocationManager.isProviderEnabled
                                                 (LocationManager.GPS_PROVIDER);
boolean isNetworkEnabled = mLocationManager.isProviderEnabled
                                             (LocationManager.NETWORK_PROVIDER);

But i strongly recommend you to use fused location. Check this and this .

Answer 3

I say nonsense, but do you use this?

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

Answer 4

Instead of using the legacy LocationManager , you should use the Google's new Fused Location API connecting to the Google Play Services, you can get the lastknown and current location, here is how to get the lastknownlocation:

 protected synchronized void buildGoogleApiClient() {
 mGoogleApiClient = new GoogleApiClient.Builder(this)
    .addConnectionCallbacks(this)
    .addOnConnectionFailedListener(this)
    .addApi(LocationServices.API)
    .build();
}


public class MainActivity extends ActionBarActivity implements
    ConnectionCallbacks, OnConnectionFailedListener {
...
@Override
public void onConnected(Bundle connectionHint) {
    mLastLocation = LocationServices.FusedLocationApi.getLastLocation(
            mGoogleApiClient);
    if (mLastLocation != null) {
        mLatitudeText.setText(String.valueOf(mLastLocation.getLatitude()));
        mLongitudeText.setText(String.valueOf(mLastLocation.getLongitude()));
      }
  }
}

For more details check official example here

And in your Manifest.xml:

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
  package="com.google.android.gms.location.sample.basiclocationsample" >

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