Question

我正在研究显示某些已连接的蓝牙低功耗设备列表的应用程序，因此用户可以选择要配置的设备之一。

问题是you can't just list all connected devices. As far as I know there are three possible ways：

使用BluetoothProfiles
```
 bluetoothManager.getConnectedDevices(BluetoothProfile.GATT_SERVER);
```
此操作失败，因为设备连接时android不会连接到GATT服务器，因此设备既不在GATT_SERVER也不在GATT配置文件下。但是，一旦我调用connectGatt方法，
```
 bluetoothDevice.connectGatt(getApplicationContext(), false, gattCallback);
```
设备可以在GATT_SERVER和GATT配置文件下找到。低能耗设备不支持其他配置文件。

列出已配对的设备，并在每个设备上尝试使用connectGatt

 List<BluetoothDevice> connectedDevices = new ArrayList<BluetoothDevice>();
 for(BluetoothDevice device : bluetoothAdapter.getBondedDevices()) {
      BluetoothGatt gatt = device.connectGatt(getApplicationContext(), false, gattCallback);
      if(gatt != null) {
          connectedDevices.add(device);
      }
      gatt.disconnect();
 }

此方法无法使用，因为它无法确定设备是否已连接或仅在范围内但未连接

在系统引导启动服务上，侦听ACL_CONNECTED and ACL_DISCONNECTED的意图并维护已连接设备的列表

清单

 <service android:name=".ManagerService" android:enabled="true" />
 <receiver
    android:name=".BootFinishedReceiver"
    android:directBootAware="true"
    android:enabled="true"
    android:exported="false"
    android:permission="android.permission.RECEIVE_BOOT_COMPLETED">

    <intent-filter>
        <action android:name="android.intent.action.BOOT_COMPLETED" />
        <action android:name="android.intent.action.LOCKED_BOOT_COMPLETED" />
        <category android:name="android.intent.category.DEFAULT" />
    </intent-filter>
</receiver>

接收器

 public class BootFinishedReceiver extends BroadcastReceiver {
      @Override
      public void onReceive(Context context, Intent intent) {
           Intent serviceIntent = new Intent(context, ManagerService.class);
           context.startService(serviceIntent);
      }
  }

服务

 public class ManagerService extends Service {
      private static List<BluetoothDevice> connectedDevices;

      @Override
      public void onCreate() {
          connectedDevices = new ArrayList<BluetoothDevice>();
          super.onCreate();
      }

      @Override
      public int onStartCommand(Intent intent, int flags, int startId) {
          IntentFilter filter = new IntentFilter();
          filter.addAction(BluetoothDevice.ACTION_ACL_CONNECTED);
          filter.addAction(BluetoothDevice.ACTION_ACL_DISCONNECTED);
          registerReceiver(connectionReceiver, filter);
          return super.onStartCommand(intent, flags, startId);
      }

      @Override
      public void onDestroy() {
          unregisterReceiver(connectionReceiver);
          super.onDestroy();
      }

      @Nullable
      @Override
      public IBinder onBind(Intent intent) {
          return null;
      }

      private final BroadcastReceiver connectionReceiver = new BroadcastReceiver() {
          @Override
          public void onReceive(Context context, Intent intent) {
              String action = intent.getAction();
              BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
              if(BluetoothDevice.ACTION_ACL_CONNECTED.equals(action)) {
                  connectedDevices.add(device);
              }else{
                  connectedDevices.remove(device);
              }
          }
      };

      public static List<BluetoothDevice> getConnectedDevices() {
          return connectedDevices;
      }
 }

Since 3.1 apps can no longer receive system intents before activity is started，因此也无法使用。

还有其他方法或现在如何在更高的android版本中实现它？

感谢任何建议

Answer 1

好吧，我发现了you can still use ON_BOOT_COMPLETED，但是必须在设备上进行设置。这样我的问题就解决了

获取android 3.1及更高版本中已连接的蓝牙低功耗设备的列表

1 个答案: