我正在使用从 Android 开发者页面上的蓝牙教程派生的代码。我的应用程序尝试连接到 BT 秤并记录重量信息。
我的程序在尝试执行 BluetoothSocket.connect() 时抛出错误；该程序作为蓝牙客户端/从属设备运行，以便从 BT 设备接收数据。用户在屏幕上看到配对设备列表，然后单击特定设备以连接到它。
因此，当用户单击特定设备时，应用程序会尝试连接到它，因为该设备已经预先配对。
应用获取 BluetoothSocket 但无法执行 connect()
我试图与其他蓝牙设备建立连接，但我总是一遍又一遍地遇到同样的错误。
下面是connectThread的java代码：
private 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;
Log.i(tag, "construct");
// 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) {
Log.i(tag, "get socket failed");
}
mmSocket = tmp;
}
public void run() {
// Cancel discovery because it will slow down the connection
btAdapter.cancelDiscovery();
Log.i(tag, "connect - run");
try {
// Connect the device through the socket. This will block
// until it succeeds or throws an exception
mmSocket.connect();
Log.i(tag, "connect - succeeded");
} catch (IOException connectException) { Log.i(tag, "connect failed");
// Unable to connect; close the socket and get out
try {
mmSocket.close();
} catch (IOException closeException) { }
return;
}
// Do work to manage the connection (in a separate thread)
mHandler.obtainMessage(SUCCESS_CONNECT, mmSocket).sendToTarget();
}
应用程序的完整代码可以在这里找到
以下是我在运行应用程序时获得的日志：
01-01 01:46:00.359: I/ActivityManager(1553): Displayed com.test.bluetooth/.Main_Activity: +579ms
01-01 01:46:00.953: D/BluetoothService(1553): updateDeviceServiceChannelCache(00:10:C6:2E:CB:C3)
01-01 01:46:00.968: D/BluetoothService(1553): updateDeviceServiceChannelCache(00:19:15:66:C4:2D)
01-01 01:46:00.984: D/BluetoothService(1553): updateDeviceServiceChannelCache(00:1A:88:00:01:25)
01-01 01:46:01.000: D/BluetoothService(1553): uuid(system): 00001105-0000-1000-8000-00805f9b34fb 1
01-01 01:46:04.421: I/debugging(2400): construct
01-01 01:46:04.421: D/BluetoothEventLoop(1553): Property Changed: Discovering : false
01-01 01:46:04.421: I/debugging(2400): in click listener
01-01 01:46:04.421: E/BluetoothService.cpp(1553): stopDiscoveryNative: D-Bus error in StopDiscovery: org.bluez.Error.Failed (Invalid discovery session)
01-01 01:46:04.429: E/BluetoothService.cpp(1553): stopDiscoveryNative: D-Bus error in StopDiscovery: org.bluez.Error.Failed (Invalid discovery session)
01-01 01:46:04.437: I/debugging(2400): connect - run
01-01 01:46:04.437: V/BluetoothDiscoveryReceiver(1864): Received: android.bluetooth.adapter.action.DISCOVERY_FINISHED
01-01 01:46:04.445: E/BluetoothEventLoop.cpp(1553): onCreateDeviceResult: D-Bus error: org.bluez.Error.AlreadyExists (Already Exists)
01-01 01:46:05.484: D/BluetoothEventLoop(1553): Device property changed: 00:10:C6:2E:CB:C3 property: Connected value: true
01-01 01:46:06.554: D/BluetoothService(1553): updateDeviceServiceChannelCache(00:10:C6:2E:CB:C3)
01-01 01:46:06.562: D/BluetoothService(1553): uuid(application): 00001101-0000-1000-8000-00805f9b34fb 1
01-01 01:46:06.562: D/BluetoothService(1553): Making callback for 00001101-0000-1000-8000-00805f9b34fb with result 1
01-01 01:46:06.562: I/debugging(2400): connect failed
01-01 01:46:06.562: W/System.err(2400): java.io.IOException: Invalid argument
01-01 01:46:06.562: W/System.err(2400): at android.bluetooth.BluetoothSocket.connectNative(Native Method)
01-01 01:46:06.562: W/System.err(2400): at android.bluetooth.BluetoothSocket.connect(BluetoothSocket.java:216)
01-01 01:46:06.562: W/System.err(2400): at com.test.bluetooth.Main_Activity$ConnectThread.run(Main_Activity.java:326)
01-01 01:46:10.132: D/BluetoothEventLoop(1553): Device property changed: 00:10:C6:2E:CB:C3 property: Connected value: false
01-01 01:47:05.914: D/SurfaceFlinger(1311): About to give-up screen, flinger = 0x41876af0
非常感谢任何/所有帮助以建立基本的 BT 连接。
谢谢你。