安卓蓝牙无法连接

Question

这个问题困扰我很久了，一直没解决。

我有一个 android 应用程序，它将所有配对的设备放在一个 ListView 中。当您单击其中一个列表项时，它将发起连接到该蓝牙设备的请求。

我可以毫无问题地获取设备列表及其地址。问题是，一旦我尝试连接，我就会在 socket.connect(); 上收到 IOException;

错误信息如下:“连接读取失败，套接字可能关闭或超时，读取 ret:-1”

这是我的代码。 任何建议将不胜感激。我非常坚持这一点。

仅供引用:“onEvent”方法是一个简化回调的库……这部分有效。当用户点击列表项时，此方法称为“public void onEvent(EventMessage.DeviceSelected event)”

public class EcoDashActivity extends BaseActivity {

public static final UUID MY_UUID = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB");


private BluetoothAdapter mBluetoothAdapter;
private int REQUEST_ENABLE_BT = 100;
private ArrayList<BluetoothDevice> mDevicesList;
private BluetoothDeviceDialog mDialog;
private ProgressDialog progressBar;
private int progressBarStatus = 0;
private Handler progressBarHandler = new Handler();


@Override
public void onCreate(final Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    requestWindowFeature(Window.FEATURE_NO_TITLE);
    setContentView(R.layout.main);

    mDevicesList = new ArrayList<BluetoothDevice>();

    // Register the BroadcastReceiver
    IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
    registerReceiver(mReceiver, filter);

    setupBluetooth();
}

private void setupBluetooth() {
    mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
    if (mBluetoothAdapter == null) {
        // Device does not support Bluetooth
        Toast.makeText(this, "Device does not support Bluetooth", Toast.LENGTH_SHORT).show();
    }

    if (!mBluetoothAdapter.isEnabled()) {
        Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
        startActivityForResult(enableBtIntent, REQUEST_ENABLE_BT);
    } else {
        searchForPairedDevices();
        mDialog = new BluetoothDeviceDialog(this, mDevicesList);
        mDialog.show(getFragmentManager(), "");
    }

}

private void searchForPairedDevices() {

    Set<BluetoothDevice> pairedDevices = mBluetoothAdapter.getBondedDevices();
    // If there are paired devices
    if (pairedDevices.size() > 0) {
        // Loop through paired devices
        for (BluetoothDevice device : pairedDevices) {
            // Add the name and address to an array adapter to show in a ListView
            mDevices.add(device.getName() + "\n" + device.getAddress());
            mDevicesList.add(device);
        }
    }
}


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
            mDevicesList.add(device);
        }
    }
};


@Override
protected void onDestroy() {
    super.onDestroy();
    unregisterReceiver(mReceiver);
}

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (requestCode == REQUEST_ENABLE_BT) {
        if (resultCode == RESULT_OK) {
            Toast.makeText(this, "BT turned on!", Toast.LENGTH_SHORT).show();
            searchForPairedDevices();

            mDialog = new BluetoothDeviceDialog(this, mDevicesList);
            mDialog.show(getFragmentManager(), "");
        }
    }

    super.onActivityResult(requestCode, resultCode, data);
}


public void onEvent(EventMessage.DeviceSelected event) {

    mDialog.dismiss();

    BluetoothDevice device = event.getDevice();

    ConnectThread connectThread = new ConnectThread(device);
    connectThread.start();
}


public class ConnectThread extends Thread {
    private final BluetoothSocket mmSocket;
    private final BluetoothDevice mmDevice;

    public ConnectThread(BluetoothDevice device) {
        // Use a temporary object that is later assigned to mmSocket,
        // because mmSocket is final
        BluetoothSocket tmp = null;
        mmDevice = device;

        // Get a BluetoothSocket to connect with the given BluetoothDevice
        try {
            // MY_UUID is the app's UUID string, also used by the server code
            tmp = device.createRfcommSocketToServiceRecord(MY_UUID);
        } catch (IOException e) { }
        mmSocket = tmp;
    }

    public void run() {
        setName("ConnectThread");
        // Cancel discovery because it will slow down the connection
        mBluetoothAdapter.cancelDiscovery();

        try {
            // Connect the device through the socket. This will block
            // until it succeeds or throws an exception
            Log.d("kent", "trying to connect to device");
            mmSocket.connect();
            Log.d("kent", "Connected!");
        } catch (IOException connectException) {
            // Unable to connect; close the socket and get out
            try {
                Log.d("kent", "failed to connect");

                mmSocket.close();
            } catch (IOException closeException) { }
            return;
        }

        Log.d("kent", "Connected!");
    }

    /** Will cancel an in-progress connection, and close the socket */
    public void cancel() {
        try {
            mmSocket.close();
        } catch (IOException e) { }
    }
}

这是我的日志。很短。

07-22 10:37:05.129: DEBUG/kent(17512): trying to connect to device
07-22 10:37:05.129: WARN/BluetoothAdapter(17512): getBluetoothService() called with no BluetoothManagerCallback
07-22 10:37:05.129: DEBUG/BluetoothSocket(17512): connect(), SocketState: INIT, mPfd: {ParcelFileDescriptor: FileDescriptor[98]}
07-22 10:37:40.757: DEBUG/dalvikvm(17512): GC_CONCURRENT freed 6157K, 9% free 62793K/68972K, paused 7ms+7ms, total 72ms
07-22 10:38:06.975: DEBUG/kent(17512): failed to connect
07-22 10:38:06.975: DEBUG/kent(17512): read failed, socket might closed or timeout, read ret: -1

最后一行在 try/catch 的“Catch”部分...我只是记录错误消息。

请注意，“尝试连接设备”和“连接失败”之间大约有 20 秒的间隔

Answer 1

果冻 bean 蓝牙堆栈与其他版本明显不同。

这可能有帮助:http://wiresareobsolete.com/wordpress/2010/11/android-bluetooth-rfcomm/

要点:UUID 是一个必须指向嵌入式设备上已发布服务的值，它不是随机生成的。您要访问的 RFCOMM SPP 连接有一个特定的 UUID，它发布该 UUID 以标识该服务，并且当您创建套接字时，它必须匹配相同的 UUID。

如果您的目标是 4.0.3 及更高版本的设备，请使用 fetchUuidsWithSdp() 和 getUuids() 查找所有已发布的服务及其关联的 UUID 值。为了向后兼容，请阅读文章