Question

我目前正在使用BLE将我的Android设备与另一个蓝牙设备连接。

问题是，如何扫描已连接的设备？

在我的第一种方法中，我没有在连接方法之前调用stopLeScan。

这对上述问题没有问题，但它导致ui中断（ui更新间隔太短），有时连接时间非常慢。

在我的应用程序在连接之前调用stopLeDevice之后，每个问题都已解决，但是出现了一个新问题。新问题是我无法再在scanResult上看到连接的设备。它仅显示断开连接的设备。我仍想监视我连接的设备。我怎么能实现这个目标呢？

Answer 1

使用此类启动自动到新的BLE设备。

BLEScanner服务

In [29]: store.get_storer('df').table
Out[29]:
/df/table (Table(10,)) ''
  description := {
  "index": Int64Col(shape=(), dflt=0, pos=0),
  "a": Int32Col(shape=(), dflt=0, pos=1),
  "b": Int32Col(shape=(), dflt=0, pos=2),
  "c": Int32Col(shape=(), dflt=0, pos=3)}
  byteorder := 'little'
  chunkshape := (3276,)
  autoindex := True
  colindexes := {
    "a": Index(6, medium, shuffle, zlib(1)).is_csi=False,
    "index": Index(6, medium, shuffle, zlib(1)).is_csi=False,
    "c": Index(6, medium, shuffle, zlib(1)).is_csi=False,
    "b": Index(6, medium, shuffle, zlib(1)).is_csi=False}

In [30]: type(store.get_storer('df').table.colindexes)
Out[30]: tables.table._ColIndexes

In [31]: type(store.get_storer('df').table.description)
Out[31]: tables.description.Description

现在用于检查BLE设备连接的回调类

public class BLEScanner extends Service {
    private BluetoothAdapter mBluetoothAdapter;
    private ArrayList<BluetoothDevice> mLeDevices;

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        mLeDevices = new ArrayList<BluetoothDevice>();
        if (getPackageManager().hasSystemFeature(PackageManager.FEATURE_BLUETOOTH_LE)) {
            BluetoothManager bluetoothManager = (BluetoothManager) getSystemService(Context.BLUETOOTH_SERVICE);
            mBluetoothAdapter = bluetoothManager.getAdapter();
        }
        startLeScan();
        return Service.START_STICKY;
    }

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

    private void startLeScan() {
        scanLeDevice(true);
    }

    private void stopLeScan() {
        scanLeDevice(false);
    }

    private void scanLeDevice(boolean enable) {
        if (enable) {
            mBluetoothAdapter.startLeScan(mLeScanCallback);
        } else {
            mBluetoothAdapter.stopLeScan(mLeScanCallback);
        }
    }

    private BluetoothAdapter.LeScanCallback mLeScanCallback = new BluetoothAdapter.LeScanCallback() {

        @Override
        public void onLeScan(BluetoothDevice device, int rssi, byte[] scanRecord) {
            if (!mLeDevices.contains(device)) {
                mLeDevices.add(device);
                connectToDevice(device);
            }
        }
    };

    private void connectToDevice(final BluetoothDevice device) {
        if (device != null) {
            Log.i("Tag", "Name: " + device.getAddress() + " Connecting");
            if (device.getName() != null)
                device.connectGatt(this.getApplicationContext(), false, new BluetoothCallBack(this.getApplicationContext(), BLEScanner.this));
        }
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        stopLeScan();
        mLeDevices.clear();
    }

    public void removeDevice(BluetoothDevice mDevice) {
        try {
            if (mLeDevices != null && mLeDevices.size() > 0)
                mLeDevices.remove(mDevice);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

Android BLE startLeScan扫描已连接的设备

1 个答案: