android 蓝牙耳机播放音乐 代码

以下是在Android上连接蓝牙耳机并播放音乐的示例代码：

private static final int REQUEST_ENABLE_BT = 1;
private BluetoothAdapter bluetoothAdapter;
private BluetoothDevice bluetoothDevice;
private MediaPlayer mediaPlayer;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    bluetoothAdapter = BluetoothAdapter.getDefaultAdapter();

    if (bluetoothAdapter == null) {
        // Device doesn't support Bluetooth
        Toast.makeText(this, "Device does not support Bluetooth", Toast.LENGTH_SHORT).show();
        return;
    }

    if (!bluetoothAdapter.isEnabled()) {
        Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
        startActivityForResult(enableBtIntent, REQUEST_ENABLE_BT);
    }

    IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
    registerReceiver(receiver, filter);

    mediaPlayer = MediaPlayer.create(this, R.raw.music);

    Button playButton = findViewById(R.id.playButton);
    playButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            if (bluetoothDevice == null) {
                Toast.makeText(MainActivity.this, "No Bluetooth device connected", Toast.LENGTH_SHORT).show();
                return;
            }

            if (!mediaPlayer.isPlaying()) {
                mediaPlayer.start();
            }
        }
    });

    Button stopButton = findViewById(R.id.stopButton);
    stopButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            if (mediaPlayer.isPlaying()) {
                mediaPlayer.pause();
                mediaPlayer.seekTo(0);
            }
        }
    });

    Button connectButton = findViewById(R.id.connectButton);
    connectButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            if (bluetoothAdapter.isDiscovering()) {
                bluetoothAdapter.cancelDiscovery();
            }

            bluetoothAdapter.startDiscovery();
        }
    });
}

@Override
protected void onDestroy() {
    super.onDestroy();

    unregisterReceiver(receiver);
}

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

        if (BluetoothDevice.ACTION_FOUND.equals(action)) {
            BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
            if (device.getName().equals("Bluetooth Headset")) {
                bluetoothDevice = device;
                Toast.makeText(MainActivity.this, "Bluetooth device connected", Toast.LENGTH_SHORT).show();
            }
        }
    }
};

在这个示例中，我们首先检查设备是否支持蓝牙，如果不支持蓝牙，则显示一条消息。然后，我们检查蓝牙是否已启用，如果未启用，则请求用户启用蓝牙。接下来，我们设置一个广播接收器来监听蓝牙设备的发现事件。当用户点击“连接”按钮时，我们开始搜索蓝牙设备。如果找到一个名为“Bluetooth Headset”的设备，则保存该设备以供播放音乐时使用。当用户点击“播放”按钮时，我们检查是否已连接蓝牙设备，如果已连接，则开始播放音乐。当用户点击“停止”按钮时，我们暂停音乐并将其重新设置到起始位置。