注：这只是个Demo 

 以下载为案例，实现开启下载，暂停下载，下载进度不断发送给activity

class DownloadService : Service() {override fun onBind(intent: Intent?): IBinder? {return MyBinder()}inner class MyBinder : Binder(){val service:DownloadServiceget() = this@DownloadService}private var mCurrentProgress:Int = 0var isStart = AtomicBoolean() fun startDownload(progress:(progress:Int)-> Unit){if (!isStart.get()){Log.d("downloadService","进度：开启")isStart.set(true)Thread(object :Runnable{override fun run() {while (isStart.get()) {try { if (mCurrentProgress<100){mCurrentProgress ++}if (mCurrentProgress>=100){isStart.set(false)}progress.invoke(mCurrentProgress) Thread.sleep(1000)} catch (e: InterruptedException) {throw RuntimeException(e)}}}} ).start() } }fun stopDownload(){if (isStart.get()){Log.d("downloadService","进度：暂停")isStart.set(false)}}}

在清单文件配置<manifest xmlns:android="http://schemas.android.com/apk/res/android"xmlns:tools="http://schemas.android.com/tools"><application ><service android:name=".activity.DownloadService"/></application></manifest>

class DownloadActivity : Activity() {override fun onCreate(savedInstanceState: Bundle?) {super.onCreate(savedInstanceState)setContentView(R.layout.activity_download)findViewById<View>(R.id.btnStart).setOnClickListener {startDownload()}findViewById<View>(R.id.btnStop).setOnClickListener {stopDownload()}}var isStartService = AtomicBoolean()fun startDownload(){if (!isStartService.get()){isStartService.set(true)Intent(this@DownloadActivity,DownloadService::class.java).apply {this.putExtra("data1","数据1")}.let {bindService(it,serviceConnection,Context.BIND_AUTO_CREATE)}}else{downloadService?.startDownload {progress->Log.d("downloadService","++ 进度：${progress}%")}}}fun stopDownload(){downloadService?.stopDownload()}var downloadService:DownloadService? = nullvar serviceConnection = object :ServiceConnection{override fun onServiceConnected(p0: ComponentName?, iBinder: IBinder?) {downloadService =  (iBinder as DownloadService.MyBinder).servicedownloadService?.startDownload {progress->Log.d("downloadService","进度：${progress}%")}}override fun onServiceDisconnected(p0: ComponentName?) {}}override fun onDestroy() {super.onDestroy()stopDownload()}
}

结果