Android 中 Service 用法和最佳实践

class SyncService : Service() {
    private val scope = CoroutineScope(SupervisorJob() + Dispatchers.IO)
    override fun onCreate() {
        super.onCreate()
        // 初始化资源
    }
    override fun onStartCommand(intent: Intent?, flags: Int, startId: Int): Int {
        scope.launch {
            try {
                // 执行耗时任务
                doSync()
            } finally {
                // 任务结束后停止服务
                stopSelf(startId)
            }
        }
        return START_NOT_STICKY
    }
    override fun onBind(intent: Intent?): IBinder? = null
    override fun onDestroy() {
        super.onDestroy()
        scope.cancel()
    }
    private suspend fun doSync() {
        // TODO: 执行同步逻辑
    }
}

ContextCompat.startForegroundService(context, Intent(context, SyncService::class.java))
// 或 context.startService(intent)（低版本或非前台需求）
context.stopService(Intent(context, SyncService::class.java))

class MusicService : Service() {
    private val binder = LocalBinder()
    inner class LocalBinder : Binder() {
        fun getService(): MusicService = this@MusicService
    }
    override fun onBind(intent: Intent): IBinder = binder
    fun play() {
        // 播放逻辑
    }
    fun pause() {
        // 暂停逻辑
    }
}

class MainActivity : AppCompatActivity() {
    private var musicService: MusicService? = null
    private var bound = false
    private val conn = object : ServiceConnection {
        override fun onServiceConnected(name: ComponentName?, service: IBinder?) {
            val binder = service as MusicService.LocalBinder
            musicService = binder.getService()
            bound = true
        }
        override fun onServiceDisconnected(name: ComponentName?) {
            bound = false
            musicService = null
        }
    }
    override fun onStart() {
        super.onStart()
        bindService(
            Intent(this, MusicService::class.java),
            conn,
            Context.BIND_AUTO_CREATE
        )
    }
    override fun onStop() {
        super.onStop()
        if (bound) {
            unbindService(conn)
            bound = false
        }
    }
}

<service
    android:name=".service.MusicService"
    android:exported="false"
    android:foregroundServiceType="mediaPlayback" />