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如何处理WorkManager Rx的结果?

android-workmanager rx-java2 rx-java kotlin android

dev.farmer · 技术社区 · 7 年前

我正在开发一个Android应用程序,使用Rx的WorkManager(Android Jetpack)。下面是工人阶级。

class ImageRxWorker(
    appContext: Context,
    private val workerParams: WorkerParameters
) : RxWorker(appContext, workerParams) {

    override fun createWork(): Single<Result> = Single.create<Result> { emitter -

        // do the job

        emitter.onSuccess(Result.success())
    }

}

工作很好,没问题。但我想知道的是我该如何处理结果?

class MainPresenter(
    private val view: MainActivity,
    private val workManager: WorkManager = WorkManager.getInstance()
) : MainContract.Presenter {

    override fun startWork(): Completable {
        view.showToastMessage(R.string.worker_started)

        return Completable.create { emitter ->
            val uploadWorkRequest = OneTimeWorkRequestBuilder<ImageRxWorker>().build()
            workManager.enqueue(uploadWorkRequest)
            emitter.onComplete() // This is not exit immediately.
        }
    }

}

我找到了“addListener”,“result”,但我不知道如何使用它们。我试着用谷歌搜索,但找不到任何好的参考资料。快来人帮帮我!

我想。。。我找到了一个解决办法。

它起作用了!!!

但是。。。它是。。。很难看。。。也不聪明。。。

(在我的应用程序中,我不使用LiveData。)

    override fun startWork(): Completable {
        view.showToastMessage(R.string.worker_started)

        return Completable.create { emitter ->
            Log.d(TAG, "[WM][Presenter] startWork - start")
            val workRequest = OneTimeWorkRequestBuilder<ImageRxWorker>()
                .setInputData(workDataOf("TIME" to 1000L))
                .build()

            workManager.enqueue(workRequest)

            while (workManager.getWorkInfoById(workRequest.id).get().state != WorkInfo.State.SUCCEEDED) {
                // Should I really polling?
                Thread.sleep(1000)
                Log.d(TAG, "[WM][Presenter] not yet......")
            }

            Log.d(TAG, "[WM][Presenter] complete")
            emitter.onComplete()
        }
    }

哇,这是“用户一号”的答案写的第三个代码。它工作得很好,看起来比第二个代码更好。因为我的应用不使用“LiveData”,所以我无法确保此代码是否有效。

在“observeForever”中,我在工人完成后调用“cancelWorkById”。对吗?

    override fun startWork(): Completable {
        view.showToastMessage(R.string.worker_started)

        return Completable.create { emitter ->
            Log.d(TAG, "[WM][Presenter] startWork - start")
            val workRequest = OneTimeWorkRequestBuilder<ImageRxWorker>()
                .setInputData(workDataOf("TIME" to 1000L))
                .build()

            workManager.enqueue(workRequest)

            workManager.getWorkInfoByIdLiveData(workRequest.id).observeForever { workInfo ->
                workInfo?.outputData?.getString("key")?.let { data ->
                    Log.d(TAG, "[WM][Presenter] startWork - complete: $data")
                    emitter.onComplete()
                    workManager.cancelWorkById(workRequest.id)
                }
            }
        }
    }

0 回复 | 直到 7 年前

User One 7 年前

使用getWorkInfoById的方法返回ListenableFuture,此方法返回LiveData:

https://developer.android.com/reference/androidx/work/WorkManager.html#getWorkInfoByIdLiveData(java.util.UUID)

与while循环不同,您可以通过观察getWorkInfoByIdleData()返回的LiveData来观察工作状态,然后在触发后调用emitter.onComplete(),但演示者中没有生命周期,因此您应该使用observeForRever()并注意移除观察者,

下面是一个例子:

workManager.getWorkInfoByIdLiveData(workRequest.id)
 .observeForever(object : Observer<WorkInfo> {
        override fun onChanged(workInfo : WorkInfo?) {
           if(workInfo.state == WorkInfo.State.SUCCEEDED) {
             ////The Work result is a Success
            }
            /* Here We remove the Observer if Not needed anymore
                 'this' here = the Observer */
         workManager.getWorkInfoByIdLiveData(workRequest.id)
          .removeObserver(this) 
        }

或者只使用getWorkInfoById()返回的ListenableFuture来获取回调