如何判断蓝牙是否已连接？

Question

有人可以教我如何查明蓝牙是否已连接到其他设备（手机、耳机等）

Answer 1

我不知道有什么方法可以获取当前连接的设备列表，但您可以使用 ACL_CONNECTED 意图监听新连接： http://developer.android.com/reference/android/bluetooth/BluetoothDevice.html#ACTION_ACL_CONNECTED

此意图包括一个额外字段，其中包含连接所用的远程设备。

在 Android 上，所有蓝牙连接都是 ACL 连接，因此注册此意图将为您提供所有新连接。

所以，你的接收器看起来像这样：

public class ReceiverBlue extends BroadcastReceiver {
  public final static String CTAG = "ReceiverBlue";
  public Set<BluetoothDevice> connectedDevices = new HashSet<BluetoothDevice>();

  public void onReceive(Context ctx, Intent intent) {

    final BluetoothDevice device = intent.getParcelableExtra( BluetoothDevice.EXTRA_DEVICE );

    if (BluetoothDevice.ACTION_ACL_CONNECTED.equalsIgnoreCase( action ) )   {
      Log.v(CTAG, "We are now connected to " + device.getName() );
      if (!connectedDevices.contains(device))
        connectedDevices.add(device);
    }

    if (BluetoothDevice.ACTION_ACL_DISCONNECTED.equalsIgnoreCase( action ) )    {
      Log.v(CTAG, "We have just disconnected from " + device.getName() );
      connectedDevices.remove(device);
    }
  }
}

Answer 2

获取当前连接的设备：

val adapter = BluetoothAdapter.getDefaultAdapter() ?: return // null if not supported
adapter.getProfileProxy(context, object : BluetoothProfile.ServiceListener {
    override fun onServiceDisconnected(p0: Int) {
    }

    override fun onServiceConnected(profile: Int, profileProxy: BluetoothProfile) {
        val connectedDevices = profileProxy.connectedDevices
        adapter.closeProfileProxy(profile, profileProxy)
    }

}, BluetoothProfile.HEADSET) // or .A2DP, .HEALTH, etc

Answer 3

我认为 getBondedDevices() 会对你有所帮助:)

Set<BluetoothDevice> pairedDevices = mBluetoothAdapter.getBondedDevices();
// If there are paired devices
if (pairedDevices.size() > 0) {
// Loop through paired devices
for (BluetoothDevice device : pairedDevices) {
    // Add the name and address to an array adapter to show in a ListView
    mArrayAdapter.add(device.getName() + "\n" + device.getAddress());
}
}

谢谢:)