我正在尝试在Android 4.4中建立蓝牙连接，但BluetoothSocket的连接方法似乎工作奇怪。我的应用程序可以假设设备已经绑定，因此我可以通过MAC地址连接。问题是它在第一次绑定设备时完美且立即连接，但如果我重新启动它，则不会建立连接并发生超时。我在while循环中执行此操作直到它连接，但实际解决方案需要很长时间，或者根本不起作用。以下是我的代码示例：
public class BluetoothManager{
private BluetoothAdapter bluetoothAdapter;
private BluetoothDevice bluetoothDevice;
private BluetoothSocket socket;
private OutputStream output;
private InputStream input;
public BluetoothManager() {
/***************/
/* Constructor */
/***************/
// lock = new Object();
bluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
}
public boolean turnOnBluetooth() {
/**************************************/
/* Turn on Bluetooth an notify result */
/**************************************/
// check if bluetooth is supported
if (bluetoothAdapter == null) {
return (false);
} else {
// enable Bluetooth if not enabled yet
if (!bluetoothAdapter.isEnabled()) {
bluetoothAdapter.enable();
}
while (!bluetoothAdapter.isEnabled()) {
Log.i("Debug", "Waiting for bluetooth to turn on");
try {
Thread.sleep(500);
} catch (Exception e) {
}
}
return (true);
}
}
public boolean turnOffBluetooth() {
/***************************************/
/* Turn off Bluetooth an notify result */
/***************************************/
// check if bluetooth is supported
if (bluetoothAdapter == null) {
return (false);
} else {
// disable Bluetooth if not enabled yet
if (bluetoothAdapter.isEnabled()) {
bluetoothAdapter.disable();
}
while (bluetoothAdapter.isEnabled()) {
Log.i("Debug
Thread.sleep(500);
} catch (Exception e) {
}
}
return (true);
}
}
public boolean configureBluetooth(String MACaddress) {
/***********************************************************************/
/* Configures to the specified bluetooth device and returns the result */
/***********************************************************************/
Log.i("Debug", "Connecting to Bluetooth Device");
bluetoothDevice = bluetoothAdapter.getRemoteDevice(MACaddress);
return (true);
}
@SuppressLint("NewApi")
public void createSocket() throws NoSuchMethodException, IllegalAccessException, IllegalArgumentException, InvocationTargetException{
final UUID serialUUID = UUID
.fromString("00001101-0000-1000-8000-00805F9B34FB");
socket = null;
output = null;
input = null;
Method m = bluetoothDevice.getClass().getMethod("createInsecureRfcommSocket", new Class[] { int.class });
socket = (BluetoothSocket)m.invoke(bluetoothDevice, 1);
}
@SuppressLint("NewApi")
public void connect() throws IOException, NoSuchMethodException, IllegalAccessException, IllegalArgumentException, InvocationTargetException {
/************************************/
/* Connects to the bluetooth device */
/************************************/
Log.i("Debug", "en connect");
while (!socket.isConnected()) { // we try until the connection is established
try {
socket.connect();
output = socket.getOutputStream();
input = socket.getInputStream();
} catch (IOException e) {
Log.i("Depuración", "Connection not established. Another run : "+e);
try {
Thread.sleep(1000);
} catch (Exception e1) {
}
}
}
}
public void terminateConnection() throws IOException {
Log.i("Debug", "terminating connection");
if(output!=null){
Log.i("Debug", "output!=null - stop streaming");
stopStreaming();
}
try {
Thread.sleep(100);
} catch (Exception e) {
}
if(input!=null){
Log.i("Debug", "input!=null");
input.close();
input=null;
}
if(output!=null){
Log.i("Depuración", "output!=null");
output.close();
output = null;
}
if(socket!=null){
Log.i("Debug", "socket!=null");
socket.close();
socket=null;
}
try {
Thread.sleep(100);
} catch (Exception e) {
}
turnOffBluetooth();
try {
Thread.sleep(100);
} catch (Exception e) {
}
try {
Thread.sleep(100);
} catch (Exception e) {
}
System.gc();
}
如果我从MainActivity调用此方法，它可以工作，但只有第一次绑定设备。如果我再次启动应用程序，我会尝试连接到设备：
socket.connect();
我怀疑它与我终止连接的方式有关，但我无法弄明白。这是方法的顺序调用：
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
bluetoothManager = new BluetoothManager();
try {
bluetoothManager.terminateConnection();
} catch (IOException e2) {
// TODO Auto-generated catch block
e2.printStackTrace();
}
bluetoothManager.turnOffBluetooth();
bluetoothManager.turnOnBluetooth();
boolean configured = false;
while (!configured) {
Log.i("Debug", "Configuration Attemp");
configured = bluetoothManager.configureBluetooth(MACaddress);
}
Log.i("Debug", "Bluetooth Configured");
try {
bluetoothManager.createSocket();
} catch (NoSuchMethodException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
} catch (IllegalAccessException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
} catch (IllegalArgumentException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
} catch (InvocationTargetException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
Log.i("Depuración", "Socket created");
try {
bluetoothManager.connect();
} catch (IOException e) {
e.printStackTrace();
} catch (NoSuchMethodException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IllegalAccessException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IllegalArgumentException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (InvocationTargetException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
Log.i("Debug", "Connected!!!!");
protected void onPause() {
Log.i("Debug", "On pause");
// TODO Auto-generated method stub
try {
bluetoothManager.terminateConnection();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
bluetoothManager = null;
System.gc();
super.onPause();
};
我一直在努力解决这个问题，我仍然找不到理由。
答案 0 :(得分：0)
嗯，我不是专业人士，但看起来你应该在应用关闭时致电bluetoothManager.terminateConnection();，让我们说onDestroy，而不是onCreate;如果之前的连接没有正确终止，我也有连接问题。只需尝试将此方法添加到您的主要活动：
@Override
public void onDestroy(){
if (bluetoothManager != null){
bluetoothManager.terminateConnection();
}
super.onDestroy();
}