蓝牙设备发现在Android上无法正常工作

Question

我正在构建一个需要通过蓝牙与其他设备通信的应用，我正在使用http://developer.android.com/guide/topics/connectivity/bluetooth.html中的以下代码。

代码运行没有任何错误，但即使在附近的设备上打开可见性也没有发现设备，但是当我打开应用程序后手动在手机上进行蓝牙设置时突然发现，我已经测试过了这个在Android 6.0和Android 4.4.2上，任何帮助将不胜感激！代码如下：

    private BluetoothAdapter mBluetoothAdapter;
    Context context;
    ListView lv;
    ArrayList<String> listItems=new ArrayList<String>();
    ArrayAdapter<String> adapter;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_checkin);
        context=getApplicationContext();
        lv=(ListView)findViewById(R.id.listView);
        mBluetoothAdapter   = BluetoothAdapter.getDefaultAdapter();
        listItems.add("Hello");
        adapter=new ArrayAdapter<String>(this,
                android.R.layout.simple_list_item_1,
                listItems);
        lv.setAdapter(adapter);

        Intent discoverableIntent = new
                Intent(BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE);
        discoverableIntent.putExtra(BluetoothAdapter.EXTRA_DISCOVERABLE_DURATION, 300);
        startActivity(discoverableIntent);
        int MY_PERMISSIONS_REQUEST_ACCESS_COARSE_LOCATION = 1;


// Register the BroadcastReceiver
        IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
        filter.addAction(BluetoothAdapter.ACTION_DISCOVERY_STARTED);
        registerReceiver(mReceiver, filter); // Don't forget to unregister during onDestroy

        mBluetoothAdapter.startDiscovery();

    }
    private final BroadcastReceiver mReceiver = new BroadcastReceiver() {
        public void onReceive(Context context, Intent intent) {
            String action = intent.getAction();
            // When discovery finds a device
            if (BluetoothDevice.ACTION_FOUND.equals(action)) {
                // Get the BluetoothDevice object from the Intent
                BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
                // Add the name and address to an array adapter to show in a ListView
                listItems.add(device.getName());
                adapter.notifyDataSetChanged();
                if(device.getName().equalsIgnoreCase("AnoudisBT")) {
                    pairDevice(device);
                    unregisterReceiver(mReceiver);
                }
            }
            if(BluetoothAdapter.ACTION_DISCOVERY_STARTED.equals(action)) {
                Log.d("antinom","Started Scan");
            }
        }
    };

    private void pairDevice(BluetoothDevice device) {
        try {
            Log.d("TAG", "Start Pairing...");

            Method m = device.getClass()
                    .getMethod("createBond", (Class[]) null);
            m.invoke(device, (Object[]) null);
            Log.d("TAG", "Pairing finished.");

        } catch (Exception e) {
            Log.e("TAG", e.getMessage());
        }
    }