Android IllegalArgumentException:无效侦听器：requestLocationUpdate为null
我正在尝试创建一个对话框来配置gps，如果在开始LocationUpdate之前此对话框处于关闭状态，则会出现以下错误。 有解决办法吗 这是主要的活动Android IllegalArgumentException:无效侦听器：requestLocationUpdate为null,android,gps,location,Android,Gps,Location,我正在尝试创建一个对话框来配置gps，如果在开始LocationUpdate之前此对话框处于关闭状态，则会出现以下错误。 有解决办法吗 这是主要的活动 public class MainActivity extends Activity { LocationManager lm; LocationListener locationListener; Context context; private TextView mLatLng; DialogSettingsGPS dialogGPS; /
public class MainActivity extends Activity {
LocationManager lm;
LocationListener locationListener;
Context context;
private TextView mLatLng;
DialogSettingsGPS dialogGPS;
// flag for GPS status
boolean isGPSEnabled = false;
// flag for network status
boolean isNetworkEnabled = false;
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//---use the LocationManager class to obtain locations data---
lm = (LocationManager)getSystemService(Context.LOCATION_SERVICE);
mLatLng = (TextView) findViewById(R.id.lat_lng);
dialogGPS = new DialogSettingsGPS(MainActivity.this);
// getting GPS status
isGPSEnabled = lm.isProviderEnabled(LocationManager.GPS_PROVIDER);
if(isGPSEnabled){
locationListener = new MyLocationListener();
}else{
dialogGPS.showSettingsAlert();
}
}
@Override
public void onResume() {
super.onResume();
lm.requestLocationUpdates(
LocationManager.GPS_PROVIDER,
10000, //mínimo tiempo de actualización
0, //mínima distancia de act.
locationListener);
}
@Override
public void onDestroy() {
super.onDestroy();
//---remove the location listener---
lm.removeUpdates(locationListener);
}
//Para escuchar los cambios el Location, se necesita crear una clase
//que implemente la interfaz de LocationListener.
private class MyLocationListener implements LocationListener
{
@Override
public void onLocationChanged(Location loc) {
if (loc != null) {
double latitude = loc.getLatitude();
double longitude = loc.getLongitude();
mLatLng.setText(getString(R.string.latitude_longitude, latitude, longitude));
}
}
@Override
public void onProviderDisabled(String provider) {
}
@Override
public void onProviderEnabled(String provider) {
}
@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
}
}
public class DialogSettingsGPS extends Service {
private final Context mContext;
public DialogSettingsGPS(Context context){
this.mContext = context;
}
/**
* Function to show settings alert dialog
* On pressing Settings button will lauch Settings Options
* */
public void showSettingsAlert(){
AlertDialog.Builder alertDialog = new AlertDialog.Builder(mContext);
// Setting Dialog Title
alertDialog.setTitle("Configuración GPS");
// Setting Dialog Message
alertDialog.setMessage("GPS desactivado. ¿Desea ir al menu de configuración?");
// On pressing Settings button
alertDialog.setPositiveButton("Configuración", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog,int which) {
Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
mContext.startActivity(intent);
}
});
// on pressing cancel button
alertDialog.setNegativeButton("Cancelar", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
dialog.cancel();
}
});
// Showing Alert Message
alertDialog.show();
}
@Override
public IBinder onBind(Intent arg0) {
// TODO Auto-generated method stub
return null;
}
}
提前感谢。如果
isGPSEnabledonResume（）