未使用 ExistingPeriodicWorkPolicy.REPLACE 替换 WorkManager

如何解决未使用 ExistingPeriodicWorkPolicy.REPLACE 替换 WorkManager

调用 ExistingPeriodicWorkPolicy.REPLACE 只是启动另一个 workManager 它不会替换另一个，多个 workManager 在触发时正在运行而不替换

val constraints = Constraints.Builder()
        .setRequiredNetworkType(NetworkType.CONNECTED)
        .build()

    val workRequest = PeriodicWorkRequestBuilder<SongsWorker>(1,TimeUnit.DAYS)
            .addTag(TAG)
            .setConstraints(constraints)
            .build()

    WorkManager.getInstance(mContext).enqueueUniquePeriodicWork(
        TAG,ExistingPeriodicWorkPolicy.REPLACE,workRequest)

日志表明工作经理至少要求取消，但执行仍在继续

I/WM-WorkerWrapper: Work [ id=6ed5487e-5d7b-4db5-a4c5-c22c562567e5,tags={ 
workerManagers.songs.SongsWorkerManager$SongsWorker } ] was cancelled
java.util.concurrent.CancellationException: Task was cancelled.
    at androidx.work.impl.utils.futures.AbstractFuture.cancellationExceptionWithCause(AbstractFuture.java:1184)
    at androidx.work.impl.utils.futures.AbstractFuture.getDoneValue(AbstractFuture.java:514)
    at androidx.work.impl.utils.futures.AbstractFuture.get(AbstractFuture.java:475)
    at androidx.work.impl.WorkerWrapper$2.run(WorkerWrapper.java:300)
    at androidx.work.impl.utils.SerialExecutor$Task.run(SerialExecutor.java:91)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1167)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:641)
    at java.lang.Thread.run(Thread.java:923)

我给工作经理附加了一个监听器，日志是

2021-04-30 20:40:54.318 17868-17868 Fragment: ID = 9f8b3165-fc75-4f9a-ba39-41c2dc6a17b3
2021-04-30 20:40:54.408 17868-17868 Fragment: ID = 9f8b3165-fc75-4f9a-ba39-41c2dc6a17b3
2021-04-30 20:40:54.427 17868-17868 Fragment: ID = 9f8b3165-fc75-4f9a-ba39-41c2dc6a17b3

听众是：

val instance = WorkManager.getInstance(requireContext())
  instance.getWorkInfosForUniqueWorkLiveData(SongsWorkerManager.TAG)
        .observe(viewLifecycleOwner) { workInfo ->
            workInfo.forEach {
                Log.d(TAG,"ID = ${it.id}")
            }
        }

在触发工作经理 3 次后，3 个相同的工作经理正在运行而不是被替换。

解决方法

以上日志并不能证明老工人没有被取消。您可以添加以下观察者通过WorkInfo

查看所有worker的当前状态

WorkManager.getInstance(context).getWorkInfosByTagLiveData(TAG)
            .observe(lifecycleOwner,{ workInfo ->
                workInfo.forEach { 
                    println("Worker Info -> $it")
                }
            })

,

如果其他人在使用 ExistingPeriodicWorkPolicy.REPLACE 阻止工作经理时遇到问题，请致电

if (isStopped) return Result.success()

在 doWork() 中，您将获得您期望的行为。

感谢

WorkManager.getInstance().cancelAllWorkByTag() not stopping the periodic job

""一种方法是在 doWork 方法中进行一些检查，通过调用 isStopped() 来检查工作线程是否已被取消。如果 isStopped 为 true，则从方法中返回一个 Result 而不是继续其余的工作。""

和

How to make sure that WorkManager cancels my Worker?