PublishSubject blockingLast()挂起Android应用程序,不调用

我在获取主体最后发出的值时遇到问题

这是我的课程,负责发射和观察电池变化:

class BatteryLevelProvider @Inject constructor(
app: App
) {

private val context: Context = app
private val receiver: PowerConnectionReceiver = PowerConnectionReceiver()

init {
initializeReceiver()
}

private fun initializeReceiver() {
IntentFilter(Intent.ACTION_BATTERY_CHANGED).let { intentFilter ->
  context.registerReceiver(receiver, intentFilter)
  }
}

companion object {
 val batteryLevelSubject = PublishSubject.create<Int>()
}

fun observeBatteryLevel(): Observable<Int> = batteryLevelSubject.distinctUntilChanged()

fun getCurrentBatteryLevel(): Int {
Timber.d("getCurrentBatteryLevel: ENTERED")
val blockingLast = batteryLevelSubject.blockingLast(0)
Timber.d("getCurrentBatteryLevel: $blockingLast")
return blockingLast
}

inner class PowerConnectionReceiver : BroadcastReceiver() {

override fun onReceive(context: Context, intent: Intent) {
  val level: Int = intent.getIntExtra(BatteryManager.EXTRA_LEVEL, -1)
  val scale: Int = intent.getIntExtra(BatteryManager.EXTRA_SCALE, -1)
  val percentage= (level / scale.toFloat() * 100).toInt()
  batteryLevelSubject.onNext(percentage)
  Timber.d("Battery changed: $percentage")
    }
  }

}

它到达了blockingLast从未得到返回值并挂起应用程序。 原因是什么?如何妥善处理?