Android 12+设备BLE扫描崩溃问题技术求助

我是Haia Consultancy的实习生，使用Kotlin开发Android应用。当前应用targetSDK设为32（对应Android 12），在S21+（Android 11）设备上执行BLE扫描时应用崩溃，低版本Android设备无此问题。错误日志提示需要android.permission.BLUETOOTH_SCAN权限，我已按官方指南配置Manifest权限、申请位置权限，甚至直接使用Android 12+适配的官方示例代码，仍然报错。检查权限时，BLUETOOTH_SCAN返回-1，尝试多种方案无效。最后发现将权限检查改为BLUETOOTH_CONNECT后代码可正常运行，但不清楚原因，求问问题根源及解决方法。

错误日志 #

2022-12-07 16:01:45.692 28797-28797 AndroidRuntime
    com...e.ultrawidebandproofofconcept  E  FATAL EXCEPTION: main
        Process: com.example.ultrawidebandproofofconcept, PID: 28797
        java.lang.SecurityException: Need android.permission.BLUETOOTH_SCAN permission for AttributionSource { uid = 10366, packageName = com.example.ultrawidebandproofofconcept, attributionTag = null, token = android.os.BinderProxy@ff32c8f, next = null }: GattService registerScanner
            at android.os.Parcel.createExceptionOrNull(Parcel.java:2438)
            at android.os.Parcel.createException(Parcel.java:2422)
            at android.os.Parcel.readException(Parcel.java:2405)
            at android.os.Parcel.readException(Parcel.java:2347)
            at android.bluetooth.IBluetoothGatt$Stub$Proxy.registerScanner(IBluetoothGatt.java:1886)
            at android.bluetooth.le.BluetoothLeScanner$BleScanCallbackWrapper.startRegistration(BluetoothLeScanner.java:519)
            at android.bluetooth.le.BluetoothLeScanner.startScan(BluetoothLeScanner.java:305)
            at android.bluetooth.le.BluetoothLeScanner.startScan(BluetoothLeScanner.java:161)
            at com.example.ultrawidebandproofofconcept.MainActivity.startBleScan(MainActivity.kt:96)
            at com.example.ultrawidebandproofofconcept.MainActivity.onCreate$lambda-0(MainActivity.kt:80)
            at com.example.ultrawidebandproofofconcept.MainActivity.$r8$lambda$NQsLDkI5TsYB6INH-F0JwBK_SNM(Unknown Source:0)
            at com.example.ultrawidebandproofofconcept.MainActivity$$ExternalSyntheticLambda2.onClick(Unknown Source:2)
            at android.view.View.performClick(View.java:7792)
            at android.widget.TextView.performClick(TextView.java:16112)
            at com.google.android.material.button.MaterialButton.performClick(MaterialButton.java:1219)
            at android.view.View.performClickInternal(View.java:7769)
            at android.view.View.access$3800(View.java:910)
            at android.view.View$PerformClick.run(View.java:30218)
            at android.os.Handler.handleCallback(Handler.java:938)
            at android.os.Handler.dispatchMessage(Handler.java:99)
            at android.os.Looper.loopOnce(Looper.java:226)
            at android.os.Looper.loop(Looper.java:313)
            at android.app.ActivityThread.main(ActivityThread.java:8751)
            at java.lang.reflect.Method.invoke(Native Method)
            at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:571)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1135)

已尝试方案 #

• 申请ACCESS_FINE_LOCATION/ACCESS_COARSE_LOCATION权限
• 在Manifest中声明BLE扫描无需关联位置信息（添加android:usesPermissionFlags="neverForLocation"）
• 使用Android官方提供的Android 12+ BLE适配示例代码

崩溃代码 #

if (ActivityCompat.checkSelfPermission(
        this,
        Manifest.permission.BLUETOOTH_SCAN
    ) != PackageManager.PERMISSION_GRANTED
) {
    requestPermissionLauncher.launch(
        Manifest.permission.BLUETOOTH_SCAN
    )
    requestPermissionLauncher.launch(
        Manifest.permission.BLUETOOTH_CONNECT
    )
    return
}
bleScanner.startScan(null, scanSettings, scanCallback)

可行代码 #

if (ActivityCompat.checkSelfPermission(
        this,
        Manifest.permission.BLUETOOTH_CONNECT
    ) != PackageManager.PERMISSION_GRANTED
) {
    requestPermissionLauncher.launch(
        Manifest.permission.BLUETOOTH_SCAN
    )
    requestPermissionLauncher.launch(
        Manifest.permission.BLUETOOTH_CONNECT
    )
    return
}
bleScanner.startScan(null, scanSettings, scanCallback)

问题根源 #

这是targetSDK版本与运行设备系统版本的权限兼容性冲突导致的：

1. BLUETOOTH_SCAN是Android 12新增的危险权限，当应用targetSDK=32时，系统要求动态申请该权限；但Android 11及以下系统中不存在这个权限，ActivityCompat.checkSelfPermission检查该权限会直接返回PERMISSION_DENIED（即-1）。
2. 崩溃代码中，因BLUETOOTH_SCAN检查未通过，进入权限申请逻辑，但Android 11系统无法识别该权限，导致requestPermissionLauncher无法弹出对应的授权对话框，权限始终无法被授予，后续执行startScan时触发SecurityException。
3. 可行代码中检查的BLUETOOTH_CONNECT同样是Android 12新增权限，但在Android 11中，系统会将该权限检查映射为旧的BLUETOOTH权限（Android 11及以下中，BLE扫描仅需BLUETOOTH和位置权限）。若已在Manifest中声明旧版BLUETOOTH权限，系统会判定BLUETOOTH_CONNECT权限已授予，跳过申请逻辑直接执行扫描，此时设备已具备所需权限，扫描正常运行。

解决方法 #

正确的做法是根据运行设备的系统版本，区分权限检查与申请逻辑：

val isAndroid12OrHigher = Build.VERSION.SDK_INT >= Build.VERSION_CODES.S
val hasRequiredPermission = if (isAndroid12OrHigher) {
    ActivityCompat.checkSelfPermission(this, Manifest.permission.BLUETOOTH_SCAN) == PackageManager.PERMISSION_GRANTED &&
    ActivityCompat.checkSelfPermission(this, Manifest.permission.BLUETOOTH_CONNECT) == PackageManager.PERMISSION_GRANTED
} else {
    ActivityCompat.checkSelfPermission(this, Manifest.permission.BLUETOOTH) == PackageManager.PERMISSION_GRANTED &&
    ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED
}

if (!hasRequiredPermission) {
    val permissionsToRequest = if (isAndroid12OrHigher) {
        arrayOf(Manifest.permission.BLUETOOTH_SCAN, Manifest.permission.BLUETOOTH_CONNECT)
    } else {
        arrayOf(Manifest.permission.BLUETOOTH, Manifest.permission.ACCESS_FINE_LOCATION)
    }
    requestPermissionLauncher.launch(permissionsToRequest)
    return
}
bleScanner.startScan(null, scanSettings, scanCallback)

同时，确保Manifest中同时声明新旧权限，覆盖不同系统版本：

<!-- 旧版本Android权限（Android 11及以下） -->
<uses-permission android:name="android.permission.BLUETOOTH" android:maxSdkVersion="30"/>
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN" android:maxSdkVersion="30"/>
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" android:maxSdkVersion="30"/>

<!-- Android 12+权限 -->
<uses-permission android:name="android.permission.BLUETOOTH_SCAN" android:usesPermissionFlags="neverForLocation"/>
<uses-permission android:name="android.permission.BLUETOOTH_CONNECT"/>

<uses-feature android:name="android.hardware.bluetooth_le" android:required="true"/>

内容的提问来源于stack exchange，提问作者SctyGmr