问在后台模式android 11+中，蓝牙无法扫描附近的设备。

EN

 <uses-permission android:name="android.permission.FOREGROUND_SERVICE" />
<uses-permission android:name="android.permission.ACCESS_BACKGROUND_LOCATION" />
 <!--BLUETOOTH PERMISSION-->
    <uses-permission android:name="android.permission.BLUETOOTH" />
    <uses-permission android:name="android.permission.BLUETOOTH_ADMIN" />
    <!-- Needed only if your app looks for Bluetooth devices.
             If your app doesn't use Bluetooth scan results to derive physical
             location information, you can strongly assert that your app
             doesn't derive physical location. -->
    <uses-permission android:name="android.permission.BLUETOOTH_SCAN" />
    <!-- Needed only if your app makes the device discoverable to Bluetooth
      devices. -->
    <uses-permission android:name="android.permission.BLUETOOTH_ADVERTISE" />
    <!-- Needed only if your app communicates with already-paired Bluetooth
           devices. -->
    <uses-permission android:name="android.permission.BLUETOOTH_CONNECT" />
    <!--bibo01 : hardware option-->
    <uses-feature android:name="android.hardware.bluetooth" android:required="false"/>
    <uses-feature android:name="android.hardware.bluetooth_le" android:required="false"/>

private var settings: ScanSettings?         = null
private val scanFilters = java.util.ArrayList<ScanFilter>()
private var mLEScanner: BluetoothLeScanner? = null
private var adapter: BluetoothAdapter?        = null




    val adapterBlu = applicationContextNew.getSystemService(Context.BLUETOOTH_SERVICE) as BluetoothManager
    adapter = adapterBlu.adapter

    mLEScanner = adapter!!.bluetoothLeScanner
    settings   = ScanSettings.Builder()
        //.setScanMode(ScanSettings.SCAN_MODE_LOW_POWER)
        .build()
    //scan specified devices only with ScanFilter
    val scanFilter = ScanFilter.Builder()
        //.setDeviceName("BIBO 1")
        .build()
    scanFilters.add(scanFilter)



  mLEScanner = adapter!!.bluetoothLeScanner
    settings   = ScanSettings.Builder()
        .build()
    //scan specified devices only with ScanFilter
    val scanFilter = ScanFilter.Builder()
        .build()
    scanFilters.add(scanFilter)

 mLEScanner!!.startScan(scanFilters, settings, highScanCallback)


//high Scan callback
private val highScanCallbackClackmass =
    object : ScanCallback() {
        override fun onScanResult(callbackType: Int, result: ScanResult) {

            
            if (result.device.name != null && result.device.address != null){
                if ("BIBO 1" == result.device.name.toString()) {
                    //globalDeviceAddress = result.device.address.toString()
                }
            }

        }
    }

val pm: PowerManager = getSystemService(POWER_SERVICE) as PowerManager
                val isScreenOn: Boolean = pm.isInteractive // check if screen is on
                if (!isScreenOn) {
                    val wl: PowerManager.WakeLock = pm.newWakeLock(PowerManager.SCREEN_DIM_WAKE_LOCK or PowerManager.ACQUIRE_CAUSES_WAKEUP, "myApp:notificationLock")
                    wl.acquire(9000) //set your time in milliseconds
                }