为什么AudioManager在RingerMode改变时崩溃？

Question

在我的应用程序中，我已经授予了phone_state的权限，并且它正在顺利地检测接收/offhook/idle统计信息。

class PhoneStateReceiver : BroadcastReceiver() {
    override fun onReceive(context: Context, intent: Intent) {

        val state = intent.getStringExtra(TelephonyManager.EXTRA_STATE)
        val incomingNumber = intent.getStringExtra(TelephonyManager.EXTRA_INCOMING_NUMBER)

        val audio = context.getSystemService(Context.AUDIO_SERVICE) as AudioManager
        if (incomingNumber == "[phone]" && state == TelephonyManager.EXTRA_STATE_RINGING) {
            Toast.makeText(context, "Ringing ${audio.ringerMode}", Toast.LENGTH_SHORT).show()
            if(audio.ringerMode == AudioManager.RINGER_MODE_SILENT)
            audio.apply {    // The app crash here!!
                ringerMode = AudioManager.RINGER_MODE_NORMAL
                setStreamVolume(AudioManager.STREAM_RING,
                        audio.getStreamMaxVolume(AudioManager.STREAM_RING),
                        AudioManager.FLAG_ALLOW_RINGER_MODES or AudioManager.FLAG_PLAY_SOUND)
            }
            val ring = RingtoneManager.getDefaultUri(RingtoneManager.TYPE_RINGTONE)
            val r = RingtoneManager.getRingtone(context, ring)
            r.play()
        }
        if (state == TelephonyManager.EXTRA_STATE_OFFHOOK) {
             audio.ringerMode = AudioManager.RINGER_MODE_SILENT
            Toast.makeText(context, "On Call ", Toast.LENGTH_SHORT).show()
        }
        if (state == TelephonyManager.EXTRA_STATE_IDLE) {
            Toast.makeText(context, "IDLE", Toast.LENGTH_SHORT).show()
        }
    }
}

<uses-permission android:name="android.permission.READ_PHONE_STATE" />

<receiver
    android:name=".broadcasts.PhoneStateReceiver">
    <intent-filter>
        <action android:name="android.intent.action.PHONE_STATE" />
    </intent-filter>
</receiver> 

更新

这是Logcat错误：

04-26 04:55:04.422 140 6-2091/？W/Audio_HW_Generic:没有向哈尔提供足够的数据，预期位置为1097356，只写了1097280 04-26 04:55:04.434 506 5-5065/？d/AndroidRuntime：关闭VM 04-26 04:55:04.446 506 5-5065/？E/AndroidRuntime：致命异常：main process:com.example.hasan.ringer，PID:5065 java.lang.securityException(parcel.java:1942)在Android.os.parcel.readException(parcel.java:1865)在Android.media.iAudioService$stub$proxy.setringerModeExterner(IAudioService.java:1161)在Android.media.audioManager.setringerMode(AudioService.java:1099)在20）在Android.view.view.performClick（view.java:6579)在Android.view.view.performClickInternal（view.java:6556)在Android.view.view.access$3100(View.java:777)在Android.view.view.view$performClick.run（view.java:25660)在Android.os.handler.handleCallback（handler.java:819)在Android.os.handler.dispatchMessage（handler.java:99)在reflect.Method.invoke（本机方法）位于com.android.internal.os.runtimeInit$methodandargscaller.run(runtimeinit.java:438)在com.android.internal.os.zygoteinit.main(zygoteinit.java:823)由：android.os.remoteException：远程堆栈跟踪：at com.android.server.audio.audioService.setringerModeExternal(AudioService.java:2333)在android.media.iAudioService$stub.onTransact(IaudioService.java:199)ActivityManager：强制完成活动com.example.hasan.ringer/.MainActivity

Answer 1

我发现答案是，access_notification_policy权限是必需的，在清单下面的required行中：

<uses-permission android:name="android.permission.ACCESS_NOTIFICATION_POLICY" />

权限是从action_notification_policy_access_settings授予的，如下所示：

val notificationManager = getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M && !notificationManager.isNotificationPolicyAccessGranted) {

        val intent = Intent(
                android.provider.Settings
                        .ACTION_NOTIFICATION_POLICY_ACCESS_SETTINGS)

        startActivity(intent)
}