自动配对2个蓝牙设备

我知道这个问题已经被问过了,但它对我不起作用。我想自动配对2台设备,而无需在设备上发出配对通知。我按照这里的指示: How to pair Bluetooth device programmatically Android 但它不起作用。事实上,我还有一个配对通知。 这是我的代码:

IntentFilter filter2 = new IntentFilter(BluetoothDevice.ACTION_PAIRING_REQUEST);
    final BroadcastReceiver mReceiver2 = new BroadcastReceiver() {
        public void onReceive(Context context, Intent intent) {
            String action = intent.getAction();
            if (BluetoothDevice.ACTION_PAIRING_REQUEST.equals(action)) {
                BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
                if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
                    int pin=intent.getIntExtra("android.bluetooth.device.extra.PAIRING_KEY", 0);
                    byte[]  pinBytes = Integer.toString(pin).getBytes();
                    device.setPin(pinBytes);
                    boolean b = device.createBond();
                }
            }
        }
    };
    registerReceiver(mReceiver2, filter2);