public void unbindAppService() {

    AppLog.d(context, "AppServiceConnection: unbindAppService");

    // detach our existing connection
    context.unbindService(serviceConnection);

    appService = null;
  }
        @Override
        public void onServiceConnected(ComponentName className, IBinder service) {

          AppLog.d(context, "ServiceConnection: onServiceConnected " + this.toString());

          appService = ((AppService.LocalBinder) service).getService();

          // executing activity's callback
          new Handler().post(runnable);
        }
  public void bindAppService() {

    if (appService != null) {
      // return;
    }

    Log.v(Constants.TAG, "AppServiceConnection: bindAppService");

    Intent i = new Intent(context, AppService.class);
    if (!context.bindService(i, serviceConnection, 0)) {
      Toast.makeText(context, "Can't connect to GPS service", Toast.LENGTH_SHORT).show();
      AppLog.d(context, "bindAppService: Can't connect to GPS service");
    }
  }
 @Override
 public void onServiceDisconnected(ComponentName className) {
   AppLog.d(context, "ServiceConnection: onServiceDisconnected");
 }