Android 蓝牙与串口设备的连接

Question

我使用了BluetoothChat示例程序中的BluetoothChatService类来进行蓝牙连接。我已经修改它像

私有静态最终 UUID MY_UUID = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB");

将其连接到串行端口设备。

我的示例测试 Android 设备是 NexusOne、HTC Desire、LG Optimus、Motorola Droid。

每当我使用应用程序将其连接到硬件时，它都会使用 NexusOne 适当地连接和断开连接。但是，当使用其他 Android 设备时，有时它们会连接，有时即使尝试了 100 次也无法连接。有时，当我断开连接时，应用程序会断开连接，但硬件上的蓝牙灯亮起，表明连接仍处于打开状态。我想知道是否是我的编码错误、硬件错误或 Android 操作系统蓝牙库错误。我在 NexusOne 上没有遇到过这个问题。我无法确定问题所在的确切位置。

有人可以指出我应该采取什么可能的行动方案来解决这个问题吗？

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提供“无法连接设备”Toast 消息的代码

/**

 * Constructor. Prepares a new BluetoothChat session.

 * @param context  The UI Activity Context

 * @param handler  A Handler to send messages back to the UI Activity

 */


public BluetoothChatService(Context context, Handler handler) {
    mAdapter = BluetoothAdapter.getDefaultAdapter();
    mState = STATE_NONE;
    mHandler = handler;
}

/**
 * Set the current state of the chat connection
 * @param state  An integer defining the current connection state
 */
private synchronized void setState(int state) {
    if (D) Log.d(TAG, "setState() " + mState + " -> " + state);
    mState = state;

    // Give the new state to the Handler so the UI Activity can update
    mHandler.obtainMessage(BluetoothChat.MESSAGE_STATE_CHANGE, state, -1).sendToTarget();
}

/**
 * Return the current connection state. */
public synchronized int getState() {
    return mState;
}

/**
 * Start the chat service. Specifically start AcceptThread to begin a
 * session in listening (server) mode. Called by the Activity onResume() */
public synchronized void start() {
    if (D) Log.d(TAG, "start");

    // Cancel any thread attempting to make a connection
    if (mConnectThread != null) {mConnectThread.cancel(); mConnectThread = null;}

    // Cancel any thread currently running a connection
    if (mConnectedThread != null) {mConnectedThread.cancel(); mConnectedThread = null;}

    setState(STATE_LISTEN);

    // Start the thread to listen on a BluetoothServerSocket
    if (mSecureAcceptThread == null) {
        mSecureAcceptThread = new AcceptThread(true);
        mSecureAcceptThread.start();
    }
    if (mInsecureAcceptThread == null) {
        mInsecureAcceptThread = new AcceptThread(false);
        mInsecureAcceptThread.start();
    }
}

/**
 * Start the ConnectThread to initiate a connection to a remote device.
 * @param device  The BluetoothDevice to connect
 * @param secure Socket Security type - Secure (true) , Insecure (false)
 */
public synchronized void connect(BluetoothDevice device, boolean secure) {
    if (D) Log.d(TAG, "connect to: " + device);

    // Cancel any thread attempting to make a connection
    if (mState == STATE_CONNECTING) {
        if (mConnectThread != null) {mConnectThread.cancel(); mConnectThread = null;}
    }

    // Cancel any thread currently running a connection
    if (mConnectedThread != null) {mConnectedThread.cancel(); mConnectedThread = null;}

    // Start the thread to connect with the given device
    mConnectThread = new ConnectThread(device, secure);
    mConnectThread.start();
    setState(STATE_CONNECTING);
}

/**
 * Start the ConnectedThread to begin managing a Bluetooth connection
 * @param socket  The BluetoothSocket on which the connection was made
 * @param device  The BluetoothDevice that has been connected
 */
public synchronized void connected(BluetoothSocket socket, BluetoothDevice
        device, final String socketType) {
    if (D) Log.d(TAG, "connected, Socket Type:" + socketType);

    // Cancel the thread that completed the connection
    if (mConnectThread != null) {mConnectThread.cancel(); mConnectThread = null;}

    // Cancel any thread currently running a connection
    if (mConnectedThread != null) {mConnectedThread.cancel(); mConnectedThread = null;}

    // Cancel the accept thread because we only want to connect to one device
    if (mSecureAcceptThread != null) {
        mSecureAcceptThread.cancel();
        mSecureAcceptThread = null;
    }
    if (mInsecureAcceptThread != null) {
        mInsecureAcceptThread.cancel();
        mInsecureAcceptThread = null;
    }

    // Start the thread to manage the connection and perform transmissions
    mConnectedThread = new ConnectedThread(socket, socketType);
    mConnectedThread.start();

    // Send the name of the connected device back to the UI Activity
    Message msg = mHandler.obtainMessage(BluetoothChat.MESSAGE_DEVICE_NAME);
    Bundle bundle = new Bundle();
    bundle.putString(BluetoothChat.DEVICE_NAME, device.getName());
    msg.setData(bundle);
    mHandler.sendMessage(msg);

    setState(STATE_CONNECTED);
}

/**
 * Stop all threads
 */
public synchronized void stop() {
    if (D) Log.d(TAG, "stop");

    if (mConnectThread != null) {
        mConnectThread.cancel();
        mConnectThread = null;
    }

    if (mConnectedThread != null) {
        mConnectedThread.cancel();
        mConnectedThread = null;
    }

    if (mSecureAcceptThread != null) {
        mSecureAcceptThread.cancel();
        mSecureAcceptThread = null;
    }

    if (mInsecureAcceptThread != null) {
        mInsecureAcceptThread.cancel();
        mInsecureAcceptThread = null;
    }
    setState(STATE_NONE);
}

/**
 * Write to the ConnectedThread in an unsynchronized manner
 * @param out The bytes to write
 * @see ConnectedThread#write(byte[])
 */
public void write(byte[] out) {
    // Create temporary object
    ConnectedThread r;
    // Synchronize a copy of the ConnectedThread
    synchronized (this) {
        if (mState != STATE_CONNECTED) return;
        r = mConnectedThread;
    }
    // Perform the write unsynchronized
    r.write(out);
}

/**
 * Indicate that the connection attempt failed and notify the UI Activity.
 */
private void connectionFailed() {
    // Send a failure message back to the Activity
    Message msg = mHandler.obtainMessage(BluetoothChat.MESSAGE_TOAST);
    Bundle bundle = new Bundle();
    bundle.putString(BluetoothChat.TOAST, "Unable to connect device");
    msg.setData(bundle);
    mHandler.sendMessage(msg);

    // Start the service over to restart listening mode
    BluetoothChatService.this.start();
}

/**
 * Indicate that the connection was lost and notify the UI Activity.
 */
private void connectionLost() {
    // Send a failure message back to the Activity
    Message msg = mHandler.obtainMessage(BluetoothChat.MESSAGE_TOAST);
    Bundle bundle = new Bundle();
    bundle.putString(BluetoothChat.TOAST, "Device connection was lost");
    msg.setData(bundle);
    mHandler.sendMessage(msg);

    // Start the service over to restart listening mode
    BluetoothChatService.this.start();
}

Answer 1

为“定制硬件”编写的服务器代码所使用的 UUID 是否与 Android 手机上使用的 UUID 匹配？ Nexus One 可能是（在您的手机中）唯一使用 Gingerbread（？） 的手机，这意味着比以前版本的 Android 具有更高的 API 级别。查看 Gingerbread 与蓝牙相关的变更日志。这可能就是原因。

Answer 2

好吧，代码有一些错误......一旦我检查了 Activity 的完整生命周期并根据该错误实现，这些错误就得到了解决。给的课很好。