即使关闭屏幕也可以开始活动 [英] Start activity even when screen is turned off

问题描述

我正在尝试通过警报启动活动. PendingIntent启动接收器，接收器启动活动.我当前的问题是活动从后台开始，无法听到警报声. 较旧的SO问题中的大多数标志对于Oreo和较新的设备均已弃用.有谁有很好的方法来解决这个问题?

I'm trying to start an activity with an alarm. The PendingIntent starts a receiver and the receiver starts the activity. My current issue is that the activity starts in the background and it's impossible to hear the alarm sound. Most of the flags from older SO questions are deprecated for Oreo and newer devices. Does anyone have a good approach how to handle this?

提前谢谢

警报创建:

alarmManager.setExact(AlarmManager.RTC_WAKEUP, intervalFinished, pendingIntent)

接收器

class OnAlarmReceiver : BroadcastReceiver() {

    override fun onReceive(context: Context, intent: Intent) {
        val intent = Intent(context, AlarmActivity::class.java)
        intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK)

        context.startActivity(intent)
    }
}

活动:

private var wake: PowerManager.WakeLock? = null

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    val powerManager = getSystemService(Context.POWER_SERVICE) as PowerManager
    wake = powerManager.newWakeLock(PowerManager.FULL_WAKE_LOCK
            or PowerManager.ACQUIRE_CAUSES_WAKEUP, "App:wakeuptag")
    wake?.acquire(10*60*1000L /*10 minutes*/)

    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O_MR1) {
        setShowWhenLocked(true)
        setTurnScreenOn(true)
    } else {
        window.addFlags(WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED
                or WindowManager.LayoutParams.FLAG_DISMISS_KEYGUARD
                or WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON
                or WindowManager.LayoutParams.FLAG_TURN_SCREEN_ON
                or WindowManager.LayoutParams.FLAG_ALLOW_LOCK_WHILE_SCREEN_ON)
    }
    setContentView(R.layout.activity_layout)
}

override fun onPause() {
    super.onPause()
    if(wake != null && wake!!.isHeld){
        wake!!.release()
    }
}

推荐答案

您应该在AndroidManifest.xml中添加

You should have in your AndroidManifest.xml

<activity
    android:name=".AlarmActivity"
    android:showOnLockScreen="true"
    android:turnScreenOn="true"/>

以下检查也应在 setContentView()之后.由于在您添加标志时，没有可以使用它们的视图.

Also the following check should be after the setContentView(). Since at the time you adding the flags there is not view that can make use of them.

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O_MR1) {
    setShowWhenLocked(true)
    setTurnScreenOn(true)
} else {
    window.addFlags(WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED
           or WindowManager.LayoutParams.FLAG_DISMISS_KEYGUARD
           or WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON
           or WindowManager.LayoutParams.FLAG_TURN_SCREEN_ON
           or WindowManager.LayoutParams.FLAG_ALLOW_LOCK_WHILE_SCREEN_ON)
}

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