如何在android中以编程方式发现蓝牙设备并在Listview中显示

Question

我尝试并遵循了一些网络教程，但它不适用于新的 Android 版本。

我声明了所有蓝牙权限并使用了 Dexter 权限库。我遵循了几个答案，但它也没有显示可用的蓝牙设备名称

下面是我的代码：

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
    scan.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            toast("starts scanning...");
            mBluetoothAdapter.startDiscovery();

        }
    });

    mAdapter = new ArrayAdapter<String>(this,android.R.layout.simple_list_item_1);
    mListView.setAdapter(mAdapter);

    mListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
           String bluetoothDevice = mAdapter.getItem(i);
           toast(bluetoothDevice);
        }
    });

}
public void pairedDevicesListView(View view){
    mAdapter.clear();

    pairedDevices = mBluetoothAdapter.getBondedDevices();

    for (BluetoothDevice device : pairedDevices){
        mAdapter.add(device.getName() + "\n" + device.getAddress());

    }
}
}

Answer 1

To discover a device, first get the bluetooth adapter by calling BluetoothAdapter.getDefaultAdapter()

BluetoothAdapter adapter = BluetoothAdapter.getDefaultAdapter();

To start discover, simply call the startDiscovery() from bluetooth adapter. This process is asynchronous so it will return immediately. To catch the discovery process, we can register a BroadcastReceiver with ACTION_FOUND, ACTION_DISCOVERY_STARTED, ACTION_DISCOVERY_STARTED. For each device found, the intent will carry extra field EXTRA_DEVICE containg the BluetoothDevice object.

IntentFilter filter = new IntentFilter();

filter.addAction(BluetoothDevice.ACTION_FOUND);
filter.addAction(BluetoothAdapter.ACTION_DISCOVERY_STARTED);
filter.addAction(BluetoothAdapter.ACTION_DISCOVERY_FINISHED);

registerReceiver(mReceiver, filter);
adapter.startDiscovery();

The receiver:

private final BroadcastReceiver mReceiver = new BroadcastReceiver() {
        public void onReceive(Context context, Intent intent) {
            String action = intent.getAction();

            if (BluetoothAdapter.ACTION_DISCOVERY_STARTED.equals(action)) {
                //discovery starts, we can show progress dialog or perform other tasks
            } else if (BluetoothAdapter.ACTION_DISCOVERY_FINISHED.equals(action)) {
                //discovery finishes, dismis progress dialog
            } else if (BluetoothDevice.ACTION_FOUND.equals(action)) {
                       //bluetooth device found
                BluetoothDevice device = (BluetoothDevice) intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);

                showToast("Found device " + device.getName());
            }
        }
    };

And, don’t forget to unregister the receiver on Activity’s onDestroy method:

@Override
    public void onDestroy() {
        unregisterReceiver(mReceiver);

        super.onDestroy();
    }