作者：Halifax

https://juejin.cn/post/7003992225575075876

正文

Android 8.0之前-常用的保活方案

Android 8.0之后-常用的保活方案

保活方案实现步骤

//前台服务
class ForegroundCoreService : Service() {
    override fun onBind(intent: Intent?): IBinder? = null
    private var mForegroundNF:ForegroundNF by lazy {
        ForegroundNF(this)
    }
     override fun onCreate() {
        super.onCreate()
        mForegroundNF.startForegroundNotification()
    }
    override fun onStartCommand(intent: Intent?, flags: Int, startId: Int): Int {
        if(null == intent){
            //服务被系统kill掉之后重启进来的
            return START_NOT_STICKY
        }
        mForegroundNF.startForegroundNotification()
        return super.onStartCommand(intent, flags, startId)
    }
    override fun onDestroy() {
        mForegroundNF.stopForegroundNotification()
        super.onDestroy()
    }
}

//初始化前台通知，停止前台通知
class ForegroundNF(private val service: ForegroundCoreService) : ContextWrapper(service) {
    companion object {
        private const val START_ID = 101
        private const val CHANNEL_ID = "app_foreground_service"
        private const val CHANNEL_NAME = "前台保活服务"
    }
    private var mNotificationManager: NotificationManager? = null    
    private var mCompatBuilder:NotificationCompat.Builder?=null   
    private val compatBuilder: NotificationCompat.Builder?
            get() {
                if (mCompatBuilder == null) {
                    val notificationIntent = Intent(this, MainActivity::class.java)
                    notificationIntent.action = Intent.ACTION_MAIN
                    notificationIntent.addCategory(Intent.CATEGORY_LAUNCHER)
                    notificationIntent.flags = Intent.FLAG_ACTIVITY_NEW_TASK or Intent.FLAG_ACTIVITY_RESET_TASK_IF_NEEDED
                    //动作意图
                    val pendingIntent = PendingIntent.getActivity(
                        this, (Math.random() * 10 + 10).toInt(),
                        notificationIntent, PendingIntent.FLAG_UPDATE_CURRENT
                    )
                    val notificationBuilder: NotificationCompat.Builder = NotificationCompat.Builder(this,CHANNEL_ID)
                    //标题
                    notificationBuilder.setContentTitle(getString(R.string.notification_content))
                    //通知内容
                    notificationBuilder.setContentText(getString(R.string.notification_sub_content))
                    //状态栏显示的小图标
                    notificationBuilder.setSmallIcon(R.mipmap.ic_coolback_launcher)
                    //通知内容打开的意图
                    notificationBuilder.setContentIntent(pendingIntent)
                    mCompatBuilder = notificationBuilder
                }
                return mCompatBuilder
            }

    init {
        createNotificationChannel()
    }

    //创建通知渠道
    private fun createNotificationChannel() {
        mNotificationManager =
            getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager
        //针对8.0+系统
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            val channel = NotificationChannel(
                CHANNEL_ID,
                CHANNEL_NAME,
                NotificationManager.IMPORTANCE_LOW
            )
            channel.lockscreenVisibility = Notification.VISIBILITY_PUBLIC
            channel.setShowBadge(false)
            mNotificationManager?.createNotificationChannel(channel)
        }
    }

    //开启前台通知
    fun startForegroundNotification() {
        service.startForeground(START_ID, compatBuilder?.build())
    }

    //停止前台服务并清除通知
    fun stopForegroundNotification() {
        mNotificationManager?.cancelAll()
        service.stopForeground(true)
    }
}

<uses-permission android:name="android.permission.REQUEST_IGNORE_BATTERY_OPTIMIZATIONS" />

//在Activity的onCreate中注册ActivityResult，一定要在onCreate中注册
//监听onActivityForResult回调
mIgnoreBatteryResultContract = registerForActivityResult(ActivityResultContracts.StartActivityForResult()) { activityResult ->
            //查询是否开启成功
            if(queryBatteryOptimizeStatus()){
               //忽略电池优化开启成功
            }else{
               //开启失败
            }
        }

val intent = Intent(Settings.ACTION_REQUEST_IGNORE_BATTERY_OPTIMIZATIONS)
intent.data = Uri.parse("package:$packageName")
//启动忽略电池优化，会弹出一个系统的弹框，我们在上面的
launchActivityResult(intent)

fun Context.queryBatteryOptimizeStatus():Boolean{
    val powerManager = getSystemService(Context.POWER_SERVICE) as PowerManager?
    return if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
        powerManager?.isIgnoringBatteryOptimizations(packageName)?:false
    } else {
        true
    }
}

//在多任务列表页面隐藏App窗口
fun hideAppWindow(context: Context,isHide:Boolean){
        try {
            val activityManager: ActivityManager = context.getSystemService(Context.ACTIVITY_SERVICE) as ActivityManager
            //控制App的窗口是否在多任务列表显示
            activityManager.appTasks[0].setExcludeFromRecents(isHide)
        }catch (e:Exception){
            .....
        }
    }