Android 扫描蓝牙设备

Android扫描蓝牙设备是个异步的过程，核心的步骤为：调用bluetoothAdapter的startDiscovery()进行设备扫描，扫描的结果通过广播接收处理！具体如下：

1.申请相关权限

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

2.注册广播

 private void registerBroadcast() {
         // Register for broadcasts when a device is discovered
         IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
         mContext.registerReceiver(mReceiver, filter);

         // Register for broadcasts when discovery has finished
         filter = new IntentFilter(BluetoothAdapter.ACTION_DISCOVERY_FINISHED);
         mContext.registerReceiver(mReceiver, filter);
     }

3.扫描设备

 private void doDiscovery() {
         // If we're already discovering, stop it
         if (mBluetoothAdapter.isDiscovering()) {
             mBluetoothAdapter.cancelDiscovery();
         }
         // Request discover from BluetoothAdapter
         mBluetoothAdapter.startDiscovery();
     }

4.广播中处理扫描到的设备

 private final BroadcastReceiver mReceiver = new BroadcastReceiver() {
         @Override
         public void onReceive(Context context, Intent intent) {
             String action = intent.getAction();

             if (BluetoothDevice.ACTION_FOUND.equals(action)) {
                 // TODO discovery finds a device

             } else if (BluetoothAdapter.ACTION_DISCOVERY_FINISHED
                     .equals(action)) {
                 // TODO discovery is finished
             }
         }
     };