current location is always null

I am trying to retrieve my current location on the button click开发者_高级运维 in an editbox using gps or network..i have tried all possible methods which i found in tutorials and older posts....but my location is always null.. i am not getting where i am wrong.? i am testing it on real device having network but no internet/gprs...

this is the code which i am using..i tried the same with GPS_PROVIDER as well ..please help me..

     protected void showCurrentLocation() 
   {
     geocoder = new Geocoder(this); 
     locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
     locationManager.requestLocationUpdates(
                LocationManager.NETWORK_PROVIDER, 
                MINIMUM_TIME_BETWEEN_UPDATES, 
                MINIMUM_DISTANCE_CHANGE_FOR_UPDATES,
                new MyLocationListener()
        );

   Location location = locationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
   System.out.println("loc.."+location);
   if (location != null) 
   {
   String message = String.format("Location \n Longitude: %1$s \n Latitude: %2$s",
                location.getLongitude(), location.getLatitude());
       Toast.makeText(ShowActivity.this, message,
               Toast.LENGTH_LONG).show();
  //acTextView.setText(message);
   try {
          List<Address> addresses = geocoder.getFromLocation(location.getLatitude(), location.getLongitude(), 10); //<10>
          for (Address address : addresses) {
              System.out.println("my location .."+address.getAddressLine(0));
            acTextView.setText(address.getAddressLine(0));
          }



        } catch (IOException e) {
          Log.e("LocateMe", "Could not get Geocoder data", e);
        }
    }
    else
    {
    AlertDialog.Builder alertbox1 = new AlertDialog.Builder(this);
    alertbox1.setMessage("No GPS or network ..Signal please fill the location manually!");
    alertbox1.setNeutralButton("Ok", new DialogInterface.OnClickListener() {
    public void onClick(DialogInterface arg0, int arg1) 
    {}});
    alertbox1.show();
    }

}   

I am just editing the question instead of asking the new one..because my problem is still related to the same...i didn't change anything in the code and this is working perfectly fine now.....But the issue is when i use the GPS_PROVIDER ,it returns the accurate address along with the value of longitude and latitude..but when i use NETWORK_PROVIDER it returns only the value of longitude and latitude no address...i want to retrieve the full address using NETWORK_PROVIDER because GPS not works indoor ...How can i do that?

Thanks...!!

pleas check your manifest file.whether have you added those permissions or not.

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

See the updated answer:

protected void showCurrentLocation() 
       {
         geocoder = new Geocoder(this); 
         locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
         locationManager.requestLocationUpdates(
                    LocationManager.NETWORK_PROVIDER, 
                    MINIMUM_TIME_BETWEEN_UPDATES, 
                    MINIMUM_DISTANCE_CHANGE_FOR_UPDATES,
                    myLocationListener
            );
         timer = new Timer();
         timer.schedule(new GetLastLocation(),20000);

       }

     class GetLastLocation extends TimerTask {

            @Override
            public void run() {
                timer.cancel();
                locationManager.removeUpdates(locationListener);
                 Location location = locationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
                   System.out.println("loc.."+location);
                   if (location != null) 
                   {
                   String message = String.format("Location \n Longitude: %1$s \n Latitude: %2$s",
                                location.getLongitude(), location.getLatitude());
                       Toast.makeText(ShowActivity.this, message,
                               Toast.LENGTH_LONG).show();
                  //acTextView.setText(message);
                   try {
                          List<Address> addresses = geocoder.getFromLocation(location.getLatitude(), location.getLongitude(), 10); //<10>
                          for (Address address : addresses) {
                              System.out.println("my location .."+address.getAddressLine(0));
                            acTextView.setText(address.getAddressLine(0));
                          }



                        } catch (IOException e) {
                          Log.e("LocateMe", "Could not get Geocoder data", e);
                        }
                    }
                    else
                    {
                    AlertDialog.Builder alertbox1 = new AlertDialog.Builder(this);
                    alertbox1.setMessage("No GPS or network ..Signal please fill the location manually!");
                    alertbox1.setNeutralButton("Ok", new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface arg0, int arg1) 
                    {}});
                    alertbox1.show();
                    }
                }   
                return;
            }
        }

     /** The location listener. */
        LocationListener myLocationListener = new LocationListener() {

            public void onLocationChanged(Location location) {

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

Another reason for getting null back from locationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER); would be if your network provider was turned off. On my phone this is toggled via Settings -> Location -> Use wireless networks.

EDIT:

You could also try:

LocationManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER)

to see if the network provider is enabled or

LocationManager.getProviders(true)

to return any enabled providers.

See http://developer.android.com/reference/android/location/LocationManager.htm for more info

Android 2.3.x SDK (API 9 and 10) emulator has bug with GPS. You should try your code on 2.2 (API 8)

when we specify NETWORK_PROVIDER to listen for location updates,

Android system makes use of wi-fi ids or internet access points to determine locations

When there is no internet access, it returns null values

Happened with me too, it doesnt get location from cell towers as expected

read into this: no gprs/no wi-fi location updates

Try this Code:

public CurrentLocation(Context ctx) {
    this.context = ctx;

    locationManager = (LocationManager) context
            .getSystemService(Context.LOCATION_SERVICE);
    @SuppressWarnings("unused")
    List<String> providers = locationManager.getAllProviders();

    Criteria locationCritera = new Criteria();
    String providerName = locationManager.getBestProvider(locationCritera,
            true);

    location = locationManager.getLastKnownLocation(providerName);
    locationListener = new MyLocationListener();

    locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0,
            0, locationListener);



}

Use this code

if (android.os.Build.VERSION.SDK_INT > 8) {

        StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
        StrictMode.setThreadPolicy(policy);

    }

And also check your Settings --> Location and security --> Use wireless networks is enabled or not.