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好吧,我找到了解决办法。。。我已经给了所有的权限 但我不知道为什么我发现,如果我手动添加“访问我的位置”权限,扫描回调就开始工作了。 所以现在我要在启动服务之前在MainActivity中实现权限请求。 这很奇怪,因为我在MainActivity内部执行BLE扫描的其他应用程序中没有遇到相同的问题;我在MainActivity中扫描的另一个应用程序没有请求这个特定的权限,它只需要“BLUETOOTH”和“BLUETOOTH”管理权限。

(我在我的设备“华为P8 Lite”上试用了Android版本“8.0.0”)

我已经在一个活动中试用了“蓝牙扫描器”,扫描过程中没有发现任何问题。

这是我的服务:

public class BLEService extends Service {

    private static final int SCAN_TIME_MILLIS = 5000;
    private static final String MY_MAC = "00:15:85:10:85:3C";

    private Handler mHandler;
    private BluetoothAdapter mBluetoothAdapter;
    private BluetoothLeScanner mScanner;
    private ScanCallback mScanCallback;
    private BluetoothGatt mBluetoothGatt;
    private BluetoothGattCallback mGattCallback;
    private int mTxpower;

    @Override
    public void onCreate() {
        super.onCreate();
        mHandler = new Handler();
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        initAll();
        startScan();
        return START_STICKY;
    }

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

    private void startScan(){
        mScanner.startScan(mScanCallback);
        mHandler.postDelayed(new Runnable() {
            @Override
            public void run() {
                stopScan();
            }
        }, SCAN_TIME_MILLIS);
    }

    private void stopScan(){
        mScanner.stopScan(mScanCallback);
        mHandler.postDelayed(new Runnable() {
            @Override
            public void run() {
                startScan();
            }
        }, SCAN_TIME_MILLIS);
    }

    private void initAll(){
        initBluetoothAdapter();
        initBluetoothLeScanner();
        initBluetoothScanCallback();
        initGattCallback();
    }

    private void initBluetoothAdapter(){
        final BluetoothManager bluetoothManager = (BluetoothManager) getBaseContext().getSystemService(Context.BLUETOOTH_SERVICE);
        mBluetoothAdapter = bluetoothManager.getAdapter();
        mBluetoothAdapter.startDiscovery();
    }

    private void initBluetoothLeScanner(){
        mScanner = mBluetoothAdapter.getBluetoothLeScanner();
    }

    private void initBluetoothScanCallback(){
        mScanCallback = new ScanCallback() {
            @Override
            public void onScanResult(int callbackType, ScanResult result) {
                super.onScanResult(callbackType, result);
            }

            @Override
            public void onBatchScanResults(List<ScanResult> results) {
                super.onBatchScanResults(results);
            }

            @Override
            public void onScanFailed(int errorCode) {
                super.onScanFailed(errorCode);
            }
        };
    }

    private void initGattCallback(){
        mGattCallback = new BluetoothGattCallback() {
            @Override
            public void onConnectionStateChange(BluetoothGatt gatt, int status, int newState) {
                super.onConnectionStateChange(gatt, status, newState);
            }

            @Override
            public void onReadRemoteRssi(BluetoothGatt gatt, int rssi, int status) {
                super.onReadRemoteRssi(gatt, rssi, status);
            }
        };
    }
}

I/蓝牙适配器:getBluetoothLeScanner

D/BluetoothLeScanner:onScannerRegistered()-状态=0 scannerId=7 mScannerId=0

所以看起来扫描是正确开始的,但是如果我尝试调试扫描的回调,它就永远不会到达断点。