CODEWITHSUNDEEP
androidgoogle-mapsgeolocationgpslocation
CoolJ Coolie
CoolJ Coolie

Reputation: 107

I cannot get GPS coordinates

My problem is that I cannot get GPS coordinates by using LocationManager class and LocationListener. This is the code I call in OnCreate():

    locMgr = (LocationManager)getSystemService(Context.LOCATION_SERVICE);
    currentLocListener = new MyLocationListener();
    locMgr.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0, currentLocListener);
    locMgr.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, currentLocListener);

And I have a class MyLocationListener that implements class LocationListener

public class MyLocationListener implements LocationListener {

@Override
public void onLocationChanged(Location location) {
    // TODO Auto-generated method stub
    String coordinates[] = {""+location.getLatitude(),""+location.getLongitude()};
    double lat = Double.parseDouble(coordinates[0]);
    double lng = Double.parseDouble(coordinates[1]);
    GeoPoint p = new GeoPoint((int)(lat*1E6), (int)(lng*1E6));
    mc.animateTo(p);
    mc.setZoom(19);

    MyMapOverlays marker = new MyMapOverlays(p);
    List<Overlay> listofOverLays = mapview.getOverlays();
    listofOverLays.clear();
    listofOverLays.add(marker);
    mapview.invalidate();
}

@Override
public void onProviderDisabled(String provider) {
    // TODO Auto-generated method stub
    Toast.makeText(getApplicationContext(), "GPS is disabled", Toast.LENGTH_SHORT).show();
}

@Override
public void onProviderEnabled(String provider) {
    // TODO Auto-generated method stub
    Toast.makeText(getApplicationContext(), "GPS is Enabled", Toast.LENGTH_SHORT).show();
}

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

I can get the location by mocking location in Emulator Control in DDMS. So I try to test on my real phone. when I install it on my phone, it can't get the current location automatically although I turned on GPS and wifi.

I try to run another google map app from market on to my real phone, it worked fine. I don't understand what is wrong with the code...can anyone help me?

LOGCAT & DEBUG

DalvikVM[localhost:8631]    
    Thread [<1> main] (Suspended (exception NullPointerException))  
        DashboardActivity$MyLocationListener.onLocationChanged(Location) line: 75   
        LocationManager$ListenerTransport._handleMessage(Message) line: 191 
        LocationManager$ListenerTransport.access$000(LocationManager$ListenerTransport, Message) line: 124  
        LocationManager$ListenerTransport$1.handleMessage(Message) line: 140    
        LocationManager$ListenerTransport$1(Handler).dispatchMessage(Message) line: 99  
        Looper.loop() line: 123 
        ActivityThread.main(String[]) line: 4627    
        Method.invokeNative(Object, Object[], Class, Class[], Class, int, boolean) line: not available [native method]  
        Method.invoke(Object, Object...) line: 521  
        ZygoteInit$MethodAndArgsCaller.run() line: 868  
        ZygoteInit.main(String[]) line: 626 
        NativeStart.main(String[]) line: not available [native method]  
    Thread [<6> Binder Thread #2] (Running) 
    Thread [<5> Binder Thread #1] (Running) 
    Thread [<7> MapService] (Running)   
    Thread [<8> TrafficService] (Running)   
    Daemon Thread [<10> [email protected]@4610b970] (Running)

LINE 75 giving error.

Upvotes: 2

Views: 2371

Answers (1)

Sean Barbeau
Sean Barbeau

Reputation: 11756

Since you're also requesting updates for the NETWORK_PROVIDER, you also need to include the permission:

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

My guess is that the line:

locMgr.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0, currentLocListener);

...is throwing a SecurityException and therefore the following line that registers the GPS_PROVIDER is never executed.

To troubleshoot, I would recommend commenting out the line that requests updates from the NETWORK_PROVIDER, and then see if GPS works on a device. Or, you can try including the above permission in your manifest, and then checking to make sure that the Locations you're receiving in the onLocationChanged() method are from the GPS_PROVIDER.

Also, try eliminating the first line where you're converting to String array. Instead, directly assign values to variables:

double lat = location.getLatitude();
double lng = location.getLongitude();

Upvotes: 2

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