尝试检测BLE设备时未调用onLeScan函数 [英] onLeScan function not called when trying to detect BLE devices

问题描述

我正在尝试检测服务附近的蓝牙低能耗设备. 服务启动后，将调用 startLeScan()，然后在10秒钟后调用 stopLeScan(). 即使 startLeScan()返回true，但我没有收到任何错误，但 LeScanCallback 上的 onLeScan 不叫. 服务:

I am trying to detect nearby Bluetooth Low-Energy devices on a service. When the service is started, startLeScan() is called, and then stopLeScan() is called after 10 seconds. Even though startLeScan() returns true, and I didn't get any error, onLeScan on the LeScanCallback was not called. the Service:

    .
    .
    .
            // Device scan callback.
        private BluetoothAdapter.LeScanCallback mLeScanCallback =
                new BluetoothAdapter.LeScanCallback() {

                    public void onLeScan(final BluetoothDevice device, final int rssi, final byte[] scanRecord) {
                        Log.i(TAG, "New LE Device: " + device.getName() + " @ " + rssi);
                        if (DEVICE_NAME.equals(device.getName()) && deviceAddress.equals(device.getAddress())) {
                            mDevice = device;
                            BleScan(false);
                            connectBluetoothDevice();
                        }
                    }
                };

    /**
     * Starts and stops Bluetooth LE scanning for BLE devices.
     *
     * @param enable true to start scanning, false to stop scanning.
     */
    public void scanLeDevice(final boolean enable) {
        if (enable) {
            // Stops scanning after a pre-defined scan period.
            mHandler.postDelayed(new Runnable() {
                @Override
                public void run() {
                    if (mScanning) {
                        BleScan(false);
                    }
                }
            }, SCAN_PERIOD);
            BleScan(true);
        } else {
            BleScan(false);
        }

    }

    /**
     * @param scan true to scan, and false to stop scanning for Bluetooth LE devices.
     */
    private void BleScan(boolean scan) {
        if (scan) {
            mScanning = true;
            boolean temp = mBluetoothAdapter.startLeScan(mLeScanCallback);
            Log.i(TAG, "Started LE scan: " + temp);
        } else {
            mScanning = false;
            mBluetoothAdapter.stopLeScan(mLeScanCallback);
        }
    }

我尝试使用 BluetoothLeScanner startScan()和 stopScan()，而是使用 ScanCallback 它没有帮助:

I tried to use BluetoothLeScanner startScan() and stopScan(), and using ScanCallback instead, but it didn't help:

    ScanCallback mScanCallback = new ScanCallback() {
        @Override
        public void onScanResult(int callbackType, ScanResult result) {
            Log.i(TAG, "New LE Device: " + result.getDevice().getName() + " @ " + result.getRssi());
        }

        @Override
        public void onScanFailed(int errorCode) {
            Log.i(TAG, "Scan Faild!!");
        }
    };


    /**
     * Starts and stops Bluetooth LE scanning for BLE devices.
     *
     * @param enable true to start scanning, false to stop scanning.
     */
    public void scanLeDevice(final boolean enable) {
        if (enable) {
            // Stops scanning after a pre-defined scan period.
            mHandler.postDelayed(new Runnable() {
                @Override
                public void run() {
                    if (mScanning) {
                        BleScan(false);
                    }
                }
            }, SCAN_PERIOD);
            BleScan(true);
        } else {
            BleScan(false);
        }

    }

    /**
     * @param scan true to scan, and false to stop scanning for Bluetooth LE devices.
     */
    private void BleScan(boolean scan) {
        if (scan) {
            mScanning = true;
            mBluetoothLeScanner.startScan(mScanCallback);
            Log.i(TAG, "Started LE scan");
        } else {
            mScanning = false;
            mBluetoothLeScanner.stopScan(mScanCallback);
        }
    }

有人说需要打开GPS，所以我打开了GPS. 我尝试重新启动android设备. 另一个BLE检测应用可以看到BLE设备.

some say GPS needs to be turned on, so I turned on GPS. I tried rebooting the android device. Another BLE detection app can see the BLE device.

为什么不调用扫描回调?

Why isn't the scan callback called?

修改

我正在运行Android 6.0.1的nexus 5设备上运行此应用程序.

I'm running this app on a nexus 5 device running Android 6.0.1 .

我尝试添加位置权限，但这没有帮助:

I tried adding location permission, but it didn't help:

( uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" )

推荐答案

我有类似的问题. 相同的代码，一种平板电脑无法正常工作，而其他平板电脑则可以正常工作. 我没有解决方案，但是当我重置平板电脑并重新安装apk时，它可以再次正常工作.

I have similar problem. Same code, one tablet not work but other does. I have no solution but when I reset my tablet and reinstall apk, it's can work fine again.

我发现了这个 onLeScan from BluetoothAdapter.LeScanCallback没有被调用Android棉花糖 当我打开GPS时，就可以了...

I found this onLeScan from BluetoothAdapter.LeScanCallback not called in Android Marshmallow when I open gps, it's work...

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