应用程序关闭时 WorkManager PeriodicWorkRequest 不起作用答案

【问题标题】：WorkManager PeriodicWorkRequest doesn't work when app closed应用程序关闭时 WorkManager PeriodicWorkRequest 不起作用
【发布时间】：2020-05-04 12:21:24
【问题描述】：

我需要在应用关闭时创建通知，我尝试执行以下方法：

NotificationWorker：


class NotificationWorker(context: Context, params: WorkerParameters) :
    CoroutineWorker(context, params) {

    private lateinit var notificationManager: NotificationManager


    override suspend fun doWork(): Result {
        initNotifications()
        notificationManager.notify(0, createNotification())
        return Result.success()
    }

    private fun initNotifications() {
        notificationManager = getSystemService(
            applicationContext,
            NotificationManager::class.java
        ) as NotificationManager

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            val importance = NotificationManager.IMPORTANCE_LOW
            val channel =
                NotificationChannel(NOTIFICATION_CHANNEL, NOTIFICATION_CHANNEL, importance)
            notificationManager.createNotificationChannel(channel)
        }
    }

    private fun createNotification(): Notification {
        val builder = if (Build.VERSION.SDK_INT < Build.VERSION_CODES.O)
            Notification.Builder(applicationContext) else
            Notification.Builder(applicationContext, NOTIFICATION_CHANNEL)

        builder.apply {
            setContentTitle("Current time")
            setContentText("${Calendar.getInstance()}")
            setSmallIcon(R.drawable.ic_launcher_foreground)
        }
        return builder.build()
    }

    companion object {
        private const val NOTIFICATION_CHANNEL = "syncended.news"

        private fun getWorkerRequest(): PeriodicWorkRequest =
            PeriodicWorkRequestBuilder<NotificationWorker>(15, TimeUnit.MINUTES).build()


        fun enqueueSelf(context: Context) {
            WorkManager.getInstance(context).enqueueUniquePeriodicWork(
                NotificationWorker::class.java.name,
                ExistingPeriodicWorkPolicy.KEEP,
                getWorkerRequest()
            )
        }
    }
}

收到电话NotificationWorker.enqueueSelf(context)

调用 onCreate 的主要活动 sendBroadcast(Intent(this,NotificationsStartReceiver::class.java))

应用：

class News : Application(), Configuration.Provider {
    override fun getWorkManagerConfiguration() =
        Configuration.Builder()
            .setMinimumLoggingLevel(android.util.Log.INFO)
            .build()
}

我在 Manifest 中创建了接收者和提供者：

<provider
    android:name="androidx.work.impl.WorkManagerInitializer"
    android:authorities="${applicationId}.workmanager-init"
    android:exported="false"
    tools:node="remove" />
<receiver
    android:name=".notifications.NotificationsStartReceiver"
    android:process=":newsBgNotify" />

应用程序运行时没问题，但是当我关闭应用程序（在任务管理器中）时，我有下一个，并且没有显示通知

2020-05-04 15:06:26.678 2046-2159/system_process W/InputDispatcher: channel '68c8279 ru.syncended.news/ru.syncended.news.main.MainActivity (server)' ~ Consumer closed input channel or an error occurred.  events=0x9
2020-05-04 15:06:26.679 2046-2159/system_process E/InputDispatcher: channel '68c8279 ru.syncended.news/ru.syncended.news.main.MainActivity (server)' ~ Channel is unrecoverably broken and will be disposed!

【问题讨论】：

标签： android android-notifications android-workmanager

【解决方案1】：

一些中国 OEM 手机（如 Oppo）在用户从最近的应用程序选项卡中滑出一个应用程序后会终止应用程序（停止后台服务）。这是造成这种情况的主要原因。要阻止这些设备这样做，请转到设置 -> 应用设置 -> “YourApp”和“启用后台服务”

【讨论】：