Android BLE（低功耗蓝牙）在Android不同版本的适配问题，华为Mate30扫描不到蓝牙模块

╰+哭是因爲堅強的太久メ 2023-01-05 01:26 812阅读 0赞

### 一、前言 ###

截止到本文完成的日期为止（2020年04月16日），笔者对Android 5.0~Android 10的部分手机进行了适配测试。该文中所遇到的问题基本都出现在国产定制系统（EMUI、MIUI、ColorOS）上。开发环境为macOS+idea。

### 二、相关代码 ###

<uses-permission android:name="android.permission.BLUETOOTH" />
    <uses-permission android:name="android.permission.BLUETOOTH_ADMIN" />
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
    <uses-permission android:name="android.permission.ACCESS_BACKGROUND_LOCATION" />
    <uses-feature
            android:name="android.hardware.bluetooth_le"
            android:required="true" />

*  \*BLE的扫描需要开启位置信息相关的权限，否则将会无法扫描到BLE设备。
    
    \*在MIUI11（Android 10）中，需要另行打开位置服务（GPS），否则也不能扫描到BLE设备。部分其它国产ROM在Android 10也可能存在此问题，解决办法同上。判断标准是：BluetoothLeScanner被正确地实例化（不为null），但始终无法发现附近的BLE设备。
 *  2、（Android 6.0及以上）在onCreate中动态申请位置信息权限：

if (Build.VERSION.SDK_INT <= Build.VERSION_CODES.M) {
        Log.i(TAG, "sdk < Android M");
        if (ActivityCompat.checkSelfPermission(this,
            Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED
            || ActivityCompat.checkSelfPermission(this,
                Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
            String[] strings =
                {Manifest.permission.ACCESS_FINE_LOCATION, Manifest.permission.ACCESS_COARSE_LOCATION};
            ActivityCompat.requestPermissions(this, strings, 1);
        }
    } else {
        if (ActivityCompat.checkSelfPermission(this,
            Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED
            || ActivityCompat.checkSelfPermission(this,
                Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED
            || ActivityCompat.checkSelfPermission(this,
                "android.permission.ACCESS_BACKGROUND_LOCATION") != PackageManager.PERMISSION_GRANTED) {
            String[] strings = {android.Manifest.permission.ACCESS_FINE_LOCATION,
                android.Manifest.permission.ACCESS_COARSE_LOCATION,
                "android.permission.ACCESS_BACKGROUND_LOCATION"};
            ActivityCompat.requestPermissions(this, strings, 2);
        }
    }

检测是否打开位置服务：

public static final boolean isLocationEnable(Context context) {
        LocationManager locationManager = (LocationManager) context.getSystemService(Context.LOCATION_SERVICE);
        boolean networkProvider = locationManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER);
        boolean gpsProvider = locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER);
        if (networkProvider || gpsProvider) return true;
        return false;
    }

如果未打开位置服务，让用户去打开：

private static final int REQUEST_CODE_LOCATION_SETTINGS = 2;
    private void setLocationService() {
        Intent locationIntent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
        this.startActivityForResult(locationIntent, REQUEST_CODE_LOCATION_SETTINGS);
    }

进入设置，让用户自己选择是否打开位置服务，然后获取选择结果：

@Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        if (requestCode == REQUEST_CODE_LOCATION_SETTINGS) {
            if (isLocationEnable(this)) {
                //定位已打开的处理
            } else {
                //定位依然没有打开的处理
            }
        } else super.onActivityResult(requestCode, resultCode, data);
    }

3、（基本）检测是否支持BLE蓝牙及蓝牙开关状态

//是否支持
    public static boolean isSupportBle(Context context) {
          if (context == null || !context.getPackageManager().hasSystemFeature(PackageManager.FEATURE_BLUETOOTH_LE)) {
              return false;
          }
          BluetoothManager manager = (BluetoothManager) context.getSystemService(Context.BLUETOOTH_SERVICE);
          return manager.getAdapter() != null;
    }
    //是否开启
    public static boolean isBleEnable(Context context) {
          if (!isSupportBle(context)) {
              return false;
          }
          BluetoothManager manager = (BluetoothManager) context.getSystemService(Context.BLUETOOTH_SERVICE);
          return manager.getAdapter().isEnabled();
    }
    //开启蓝牙
    public static void enableBluetooth(Activity activity, int requestCode) {
          Intent intent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
          activity.startActivityForResult(intent, requestCode);
    }

4、（基本&&Android 7.0+适配特别注意！）进行BLE设备扫描

在Android 7.0及以后的系统中，BluetoothAdapter.startLeScan()方法被废弃，所以需要根据系统版本的不同来执行不同的扫描方法，否则在MIUI11及EMUI10的部分机型上会扫描不到BLE设备。

private void startScan() throws Exception {
            isScanning = true;
            handler.postDelayed(scanRunnable, TIME_OUT);
            BluetoothManager bluetoothManager = (BluetoothManager) getSystemService(Context.BLUETOOTH_SERVICE);
            if (Build.VERSION.SDK_INT <= Build.VERSION_CODES.M) {
                LogUtil.e("系统版本：","<7.0");
                bluetoothManager.getAdapter()
                        .startLeScan(mLeScanCallback);
            } else {//安卓7.0及以上的方案
                LogUtil.e("系统版本：",">=7.0");
                bleScanner = bluetoothManager.getAdapter().getBluetoothLeScanner();
                bleScanner.startScan(scanCallback);
            }
        }

//停止扫描
        private void stopScan() {
            isScanning = false;
            BluetoothManager bluetoothManager = (BluetoothManager) getSystemService(Context.BLUETOOTH_SERVICE);
            if (Build.VERSION.SDK_INT <= Build.VERSION_CODES.M) {
                //安卓6.0及以下版本BLE操作的代码
                bluetoothManager.getAdapter().stopLeScan(mLeScanCallback);
            } else
                //安卓7.0及以上版本BLE操作的代码
                bleScanner.stopScan(scanCallback);
        }

//扫描结果回调-Android 7.0-
        private BluetoothAdapter.LeScanCallback mLeScanCallback = new BluetoothAdapter.LeScanCallback() {
            @SuppressLint("HandlerLeak")
            @Override
            public void onLeScan(BluetoothDevice device, int rssi, byte[] scanRecord) {
                LogUtil.e(TAG, "开始搜索设备：" + mac);
                if (device.getAddress().equals(mac)) {
                    LogUtil.e(TAG, "搜索到设备 " + mac);
                    new Handler() {
                        @Override
                        public void handleMessage(Message msg) {
                            if (mBluetoothLeService != null) {
                                mBluetoothLeService.connect(mac);
                            }
                        }
                    }.sendEmptyMessageDelayed(3000, 200);
                    stopScan();
                    isScanning = false;
                    handler.removeCallbacks(scanRunnable);
                }
            }
        };
    
    //扫描结果回调-7.0+
        private ScanCallback scanCallback = new ScanCallback() {
            @SuppressLint("HandlerLeak")
            @RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
            @Override
            public void onScanResult(int callbackType, ScanResult result) {
                super.onScanResult(callbackType, result);
                BluetoothDevice device = result.getDevice();
                String macAddr = device.getAddress();
                LogUtil.e("发现设备：", macAddr);
                if (macAddr.equals(mac)) {
                    LogUtil.e(TAG, "搜索到匹配的蓝牙设备(6.0+): " + mac);
                    new Handler() {
                        @Override
                        public void handleMessage(Message msg) {
                            if (mBluetoothLeService != null) {
                                mBluetoothLeService.connect(mac);
                            }
                        }
                    }.sendEmptyMessageDelayed(3000, 200);
                    stopScan();
                    isScanning = false;
                    handler.removeCallbacks(scanRunnable);
                }
                Log.i(TAG, macAddr);
            }
        };

//重连计时器
    private Runnable scanRunnable = new Runnable() {
            @Override
            public void run() {
                connTimeOutTimes++;
                LogUtil.e(TAG, "重连第" + connTimeOutTimes + "次");
                if (connTimeOutTimes < RECONNECT_TIMES) {
                    handler.postDelayed(scanRunnable, TIME_OUT);
                } else {
                    stopScan();
                    connTimeOutTimes = 0;
                    if (connectFunction != null) {
                        LogUtil.e(TAG, "连接超时：" + mBluetoothLeService.getConnectState());
                        connectFunction.onCallBack("{\"code\":-1,\"msg\":\"连接超时\",\"data\":\"false\"}");
                        connectFunction = null;
                    }
                    if (cardConnectFunction != null) {
                        cardConnectFunction.onCallBack("{\"code\":-1,\"msg\":\"连接超时\",\"data\":\"false\"}");
                        cardConnectFunction = null;
                    }
                    mBluetoothLeService.setConnectionState(0);
                    mBluetoothLeService.release();
                    bindStatus = 0;
                }
            }
        };

### 三、踩过坑的机型/ROM ###

*  1、小米/红米
    
    MIUI11：必须打开位置服务才可搜索到BLE设备；
    
    MIUI11及更早：
    
    初始化BlueToothGatt时务必将connectGatt的autoConnect设为false，否则会被系统杀掉；

package android.bluetooth;
    public final class BluetoothDevice implements Parcelable {
    ...
    public BluetoothGatt connectGatt(Context context, boolean autoConnect,
                BluetoothGattCallback callback) {
            return (connectGatt(context, autoConnect, callback, TRANSPORT_AUTO));
        }
    }

必须针对Android M及以上的MIUI配置调用BluetoothLeScanner.startScan()方法来搜索BLE设备，而非被废弃的BluetoothAdapter.startLeScan()，否则将无法搜索到设备，日志如下：

D/BluetoothAdapter: startLeScan(): null					**注意，此处为null
    D/BluetoothAdapter: isLeEnabled(): ON
    D/BluetoothLeScanner: onScannerRegistered() - status=0 scannerId=6 mScannerId=0

*  2、华为/荣耀
    
    EMUI10（仅Mate 30/P30系列）：必须打开位置服务才可搜索到BLE设备
 *  3、部分国产ROM（包括上述两类）：
    
    部分机型需打开位置服务才可搜索到BLE设备；
    
    部分机型需动态申请位置权限才可搜索到BLE设备；
    
    部分机型需将connectGatt的autoConnect设为false（MIUI、ColorOS）；
    
    部分机型需针对Android M及以上的系统版本配置调用BluetoothLeScanner.startScan()方法来搜索BLE设备；

### 四、附录：连接日志（MIUI） ###

E/系统版本：: >=6.0
    D/BluetoothAdapter: isLeEnabled(): ON
    D/BluetoothLeScanner: onScannerRegistered() - status=0 scannerId=8 mScannerId=0
    E/发现设备：: xx:xx:xx:xx:xx:xx
    E/WebViewActivity: 搜索到匹配的蓝牙设备(6.0+): xx:xx:xx:xx:xx:xx
    D/BluetoothAdapter: isLeEnabled(): ON
    I/WebViewActivity: xx:xx:xx:xx:xx:xx
    E/BlueToothService: xx:xx:xx:xx:xx:xx
    D/BluetoothGatt: onClientConnectionState() - status=0 clientIf=7 device=xx:xx:xx:xx:xx:xx
    D/BluetoothGatt: discoverServices() - device: xx:xx:xx:xx:xx:xx
    E/WebViewActivity: 连接成功：2
    D/BluetoothGatt: onConnectionUpdated() - Device=xx:xx:xx:xx:xx:xx interval=6 latency=0 timeout=500 status=0
    D/BluetoothGatt: onSearchComplete() = Device=xx:xx:xx:xx:xx:xx Status=0
    D/BluetoothGatt: setCharacteristicNotification() - uuid: 0000fff4-xxxx-xxxx-xxxx-00xxxx9bxxxx enable: true
    D/BluetoothGatt: onConnectionUpdated() - Device=xx:xx:xx:xx:xx:xx interval=36 latency=0 timeout=500 status=0

完！！！