android - 多次调用 startLeScan 方法不能正确扫描 BLE 设备

Question

我试图在我的 Android 应用程序中多次调用 startLeScan 方法，它第一次扫描 BLE 设备，从第二次开始它无法扫描设备。我在我的应用程序中进行了循环扫描，每 10 秒停止一次扫描并重新开始。这里有一些日志显示了我的应用程序的行为方式。

05-20 00:45:31.146  15841-15841/XXXXX D/BluetoothAdapter﹕ stopLeScan()
05-20 00:45:31.147  15841-15841/XXXXX D/BluetoothAdapter﹕ startLeScan(): null
05-20 00:45:31.160  15841-15852/XXXXX D/BluetoothAdapter﹕ onClientRegistered() - status=133 clientIf=0
05-20 00:45:31.161  15841-15841/XXXXX D/BluetoothAdapter﹕ stopLeScan()
05-20 00:45:31.165  15841-15841/XXXXX D/BluetoothAdapter﹕ startLeScan(): null
05-20 00:45:31.169  15841-15909/XXXXX D/BluetoothAdapter﹕ onClientRegistered() - status=0 clientIf=7
05-20 00:45:31.171  15841-15841/XXXXX D/BluetoothAdapter﹕ stopLeScan()
05-20 00:45:31.175  15841-15841/XXXXX D/BluetoothAdapter﹕ startLeScan(): null
05-20 00:45:31.179  15841-15853/XXXXX D/BluetoothAdapter﹕ onClientRegistered() - status=0 clientIf=8
05-20 00:45:31.181  15841-15841/XXXXX D/BluetoothAdapter﹕ stopLeScan()
05-20 00:45:31.185  15841-15841/XXXXX D/BluetoothAdapter﹕ startLeScan(): null
05-20 00:45:31.189  15841-18615/XXXXX D/BluetoothAdapter﹕ onClientRegistered() - status=0 clientIf=6
05-20 00:45:31.191  15841-15841/XXXXX D/BluetoothAdapter﹕ stopLeScan()
05-20 00:45:31.192  15841-15841/XXXXX D/BluetoothAdapter﹕ startLeScan(): null
05-20 00:45:31.202  15841-15852/XXXXX D/BluetoothAdapter﹕ onClientRegistered() - status=133 clientIf=0
05-20 00:45:31.203  15841-15841/XXXXX D/BluetoothAdapter﹕ stopLeScan()
05-20 00:45:31.207  15841-15841/XXXXX D/BluetoothAdapter﹕ startLeScan(): null
05-20 00:45:31.211  15841-15909/XXXXX D/BluetoothAdapter﹕ onClientRegistered() - status=0 clientIf=10

我的 BluetoothLEScannerForMR2.java 中有这些函数调用，当我多次调用 startScan 方法时，我得到了上述日志。

protected void startScan() {
    if (getBluetoothAdapter() != null) {
        if (getBluetoothAdapter().isEnabled()) {
            getBluetoothAdapter().startLeScan(mLeScanCallback);
            mScanStopTime = new Date().getTime() + mScanPeriod;

            mScanning = true;

            handleIntervalScanning();
        }
    }
}

protected void stopScan() {
    if (getBluetoothAdapter() != null) {
        if (getBluetoothAdapter().isEnabled()) {
            getBluetoothAdapter().stopLeScan(mLeScanCallback);
            mScanning = false;
        }
    }
}

private void handleIntervalScanning() {
    long msUntilNextStop = mScanStopTime - (new Date().getTime());

    if (msUntilNextStop > mScanPeriod)
        msUntilNextStop =  mScanPeriod;

    if (msUntilNextStop > 0) {
        mHandler.postDelayed(new Runnable() {
            @Override
            public void run() {
                handleIntervalScanning();
            }
        }, msUntilNextStop);
    } else {
        if (getBluetoothAdapter() != null) {
            if (getBluetoothAdapter().isEnabled()) {
                if (mScanning) {
                    getBluetoothAdapter().stopLeScan(mLeScanCallback);

                    startScan();
                }
            }
        }
    }
}

Answer 1

这是一篇旧帖子，但我想我会发表评论以防其他人需要帮助。在您的代码中，您获得了 BlueToothAdapter 的一个实例并调用了 startscan 方法……但是您没有保留该适配器实例。然后在您的 stopscan 方法中，您创建一个蓝牙适配器的新实例并调用它的停止扫描。我认为您需要在“获取”适配器时将适配器保存到内存变量，然后使用适配器的相同实例(通过内存变量)停止扫描。