Android 蓝牙

努力尽今夕，少年犹可夸。这篇文章主要讲述Android 蓝牙相关的知识，希望能为你提供帮助。
首先需要添加权限

< uses-permission android:name="android.permission.BLUETOOTH"/> < uses-permission android:name="android.permission.BLUETOOTH_ADMIN"/>

Android中的蓝牙是通过BluetoothAdapter来操作的,

//先获取BlueToothAdapter的实例 BluetoothAdapter blueToothAdapter=BluetoothAdapter.getDefaultAdapter();

打开蓝牙,断开蓝牙

//判断蓝牙是否打开 if (!bluetoothAdapter.isEnabled()) { //第一种调用enable()直接打开 bluetoothAdapter.enable(); //断开蓝牙 bluetoothAdapter.disable(); Toast.makeText(this, "蓝牙功能已开启", Toast.LENGTH_SHORT).show(); }

设置蓝牙可见性,能被周围设备扫描到

if (bluetoothAdapter.getScanMode() != BluetoothAdapter.SCAN_MODE_CONNECTABLE_DISCOVERABLE) { Intent discoverableIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE); //设置最多可见时间为300秒 discoverableIntent.putExtra(BluetoothAdapter.EXTRA_DISCOVERABLE_DURATION, 300); startActivity(discoverableIntent); }

蓝牙的搜索功能

blueToothAdapter.startDiscovery();

当搜索到设备后系统会以广播的形式接收,自定义一个广播

class BluetoothReceiver extends BroadcastReceiver {@Override public void onReceive(Context context, Intent intent) {if (intent.getAction().equals(BluetoothDevice.ACTION_FOUND)) { Log.e(getPackageName(), "找到新设备了"); BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE); } } }

注册广播

//注册广播 IntentFilter intentFilter = new IntentFilter(); intentFilter.addAction(BluetoothDevice.ACTION_FOUND); registerReceiver(new BluetoothReceiver(), intentFilter);

注意，如果你的代码将运行在（Build.VERSION.SDK_INT > = 23）的设备上，需要获取设备的定位权限才能进行蓝牙搜索功能，并在代码中动态的申请权限.

< uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" /> < uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />

动态申请权限

private void requestPermission() { if (Build.VERSION.SDK_INT > = 23) { int checkAccessFinePermission = ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION); if (checkAccessFinePermission != PackageManager.PERMISSION_GRANTED) { ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.ACCESS_FINE_LOCATION}, REQUEST_PERMISSION_ACCESS_LOCATION); Log.e(getPackageName(), "没有权限，请求权限"); return; } Log.e(getPackageName(), "已有定位权限"); //这里可以开始搜索操作 } }@Override public void onRequestPermissionsResult(int requestCode, String permissions[], int[] grantResults) { switch (requestCode) { case REQUEST_PERMISSION_ACCESS_LOCATION: { if (grantResults.length > 0 & & grantResults[0] == PackageManager.PERMISSION_GRANTED) {Log.e(getPackageName(), "开启权限permission granted!"); //这里可以开始搜索操作 } else { Log.e(getPackageName(), "没有定位权限，请先开启!"); } } } super.onRequestPermissionsResult(requestCode, permissions, grantResults); }

蓝牙的配对,调用BluetoothDevice的createBondde()方法，如果我们想监听配对的这个过程，那么我们可以为广播接收器再注册一个action。

try { Method method = null; method = BluetoothDevice.class.getMethod("createBond"); Log.e(getPackageName(), "开始配对"); method.invoke(device); flag = true; } catch (NoSuchMethodException | InvocationTargetException | IllegalAccessException e) { Log.e(getPackageName(), "配对失败"); e.printStackTrace(); }

如果想监听配对过程,可以通过广播的形式,在注册一个action

//绑定状态发生变化 intentFilter.addAction(BluetoothDevice.ACTION_BOND_STATE_CHANGED);

广播接收器中

if (intent.getAction().equals(BluetoothDevice.ACTION_BOND_STATE_CHANGED)) { BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE); switch (device.getBondState()) { case BluetoothDevice.BOND_NONE: Log.e(getPackageName(), "取消配对"); break; case BluetoothDevice.BOND_BONDING: Log.e(getPackageName(), "配对中"); break; case BluetoothDevice.BOND_BONDED: Log.e(getPackageName(), "配对成功"); break; } }

配对设配发送数据
发送数据分为客户端和服务端,通过Socket来进行消息交互
服务端

new Thread(new Runnable() { @Override public void run() { InputStream is = null; try { BluetoothServerSocket serverSocket = blueToothAdapter.listenUsingRfcommWithServiceRecord("serverSocket", uuid); mHandler.sendEmptyMessage(startService); BluetoothSocket accept = serverSocket.accept(); is = accept.getInputStream(); byte[] bytes = new byte[1024]; int length = is.read(bytes); Message msg = new Message(); msg.what = getMessageOk; msg.obj = new String(bytes, 0, length); mHandler.sendMessage(msg); } catch (IOException e) { e.printStackTrace(); } } }).start();

客户端

new Thread(new Runnable() { @Override public void run() { OutputStream os = null; try { BluetoothSocket socket = strArr.get(i).createRfcommSocketToServiceRecord(uuid); socket.connect(); os = socket.getOutputStream(); os.write("testMessage".getBytes()); os.flush(); mHandler.sendEmptyMessage(sendOver); } catch (Exception e) { e.printStackTrace(); } } }).start();

可以看到无论是服务端还是客户端，都需要新起一个子线程来操作。那么服务端和客户端是怎么识别对方的呢，那么就需要用到UUID了，只有当服务端和客户端的UUID相同的时候才能够建立连接。