CoroutineWorker 的主要特点：
-
Kotlin 协程支持：通过使用 Kotlin 协程，
CoroutineWorker提供了更自然和可读的异步编程模型，避免了复杂的回调嵌套问题。 -
后台任务：它允许开发者在后台执行任务，比如数据同步、图片上传、定期执行任务等，而不需要担心任务被中断，即使应用关闭或重启，任务仍会在条件满足时继续执行。
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持久性和约束条件：与普通的后台线程不同，
CoroutineWorker可以设置任务的执行条件，比如仅在设备充电、联网等条件满足时执行。WorkManager会确保这些条件符合时，任务才会被执行。
package com.plcoding.globalsnackbarscompose.workerimport android.content.Context
import android.graphics.Bitmap
import android.graphics.BitmapFactory
import android.net.Uri
import androidx.work.CoroutineWorker
import androidx.work.WorkerParameters
import androidx.work.workDataOf
import kotlinx.coroutines.Dispatchers
import kotlinx.coroutines.withContext
import java.io.ByteArrayOutputStream
import java.io.File
import kotlin.math.roundToIntclass PhotoCompressionWorker(private val appContex: Context,private val params: WorkerParameters
) : CoroutineWorker(appContex, params) {override suspend fun doWork(): Result {return withContext(Dispatchers.IO) {println("workder doWork")val stringUri = params.inputData.getString(KEY_CONTENT_URI)val compressThresHold = params.inputData.getLong(KEY_COMPRESSION_TH, 0L)val uri = Uri.parse(stringUri)val bytes = appContex.contentResolver.openInputStream(uri)?.use {it.readBytes()} ?: return@withContext Result.failure()val bitmap = BitmapFactory.decodeByteArray(bytes, 0, bytes.size)var outputBytes: ByteArrayvar quality = 100do {val outputStream = ByteArrayOutputStream()outputStream.use { outputStream ->bitmap.compress(Bitmap.CompressFormat.JPEG, quality, outputStream)outputBytes = outputStream.toByteArray()quality -= (quality * 0.1).roundToInt()}} while (outputBytes.size > compressThresHold && quality > 5)val file = File(appContex.cacheDir,"${params.id}.jpg")file.writeBytes(outputBytes)Result.success(workDataOf(KEY_RESULT_PATH to file.absoluteFile.toString()))}}companion object {const val KEY_CONTENT_URI = "KEY_CONTENT_URI"const val KEY_COMPRESSION_TH = "KEY_COMPRESSION_TH"const val KEY_RESULT_PATH = "KEY_RESULT_PATH"}
}根据图片，因为不知道图片多大，还一次次的压缩，直到达到压缩的指标大小了，将文件写入文件
怎么启动这个woker呢
workManager = WorkManager.getInstance(applicationContext)
fun requestWorker(uri: Uri, workManager: WorkManager) {val result = OneTimeWorkRequestBuilder<PhotoCompressionWorker>().setInputData(workDataOf(PhotoCompressionWorker.KEY_CONTENT_URI to uri.toString(),PhotoCompressionWorker.KEY_COMPRESSION_TH to 1024 * 20L)).setConstraints(Constraints(requiresStorageNotLow = true)).build()workManager.enqueue(result)}作为后台任务
