android 内部注册receiver

BroadcastReceiver b1 = null;
 
 
 @Override
  protected void onCreate(Bundle savedInstanceState) {b1 = new BroadcastReceiver() {
    @Override
    public void onReceive(Context context, Intent intent) {
     Bundle bundle = intent.getExtras();
     int progress = bundle.getInt("progress");
     // Log.e(this.getClass().getName(), "onReceive()" + progress);
     progressBar.setProgress(progress);
    }
   };
   IntentFilter mFilter = new IntentFilter();
   mFilter.addAction("update_progressbar");
   registerReceiver(b1, mFilter); 
}
 
 
@Override
  protected void onDestroy() {
   super.onDestroy();
   unregisterReceiver(b1);
   b1 = null;
  }