Android前台服务同一个服务有多个通知？

Question

我正在开发一款闹钟应用程序，我面临的问题是，当一个闹钟响起并且新闹钟启动时，新闹钟的通知会取代现有的通知。我希望两个通知同时显示，而新通知不会取消前一个通知。

服务代码

package com.example.alarmclock.service


import android.app.NotificationManager
import android.app.PendingIntent
import android.app.Service
import android.content.Context
import android.content.Intent
import android.media.AudioManager
import android.os.IBinder
import androidx.core.app.NotificationCompat
import com.example.alarmclock.R
import com.example.alarmclock.common.AlarmSound
import com.example.alarmclock.common.Constant.EXTRA_ID
import com.example.alarmclock.common.Constant.EXTRA_MESSAGE
import com.example.alarmclock.common.Constant.EXTRA_SOUND
import com.example.alarmclock.common.Constant.EXTRA_TIME
import com.example.alarmclock.common.Constant.NOTIFICATION_CHANNEL_ID
import com.example.alarmclock.common.formatCurrentTime

import com.example.alarmclock.presentation.alarm_challenge_screen.ui.AlarmChallengeScreen
import java.util.Calendar


class AlarmsService : Service() {

    private var alarmSound: AlarmSound? = null


    override fun onStartCommand(intent: Intent?, flags: Int, startId: Int): Int {


        val id = intent?.getIntExtra(EXTRA_ID, 0) ?: return START_NOT_STICKY
        val message = intent.getStringExtra(EXTRA_MESSAGE) ?: ""
        val soundResId = intent.getIntExtra(EXTRA_SOUND, R.raw.default_sound)
        val time = Calendar.getInstance().formatCurrentTime()

        displayNotification(
                id,
                this,
                 "Alarm Triggered : $time",
                 "Message: $message",
                createAlarmChallengeScreenIntent(this, time, id)
        )

        alarmSound?.release()
        alarmSound = AlarmSound(this, soundResId).apply { startSound() }

        return START_STICKY
    }

    override fun onBind(intent: Intent): IBinder? {
        return null
    }


    override fun onDestroy() {
        alarmSound?.release()
        super.onDestroy()
    }


    private fun displayNotification(
        id: Int,
        context: Context,
        title: String,
        description: String,

        openAlarmChallengeScreenIntent: PendingIntent
    ) {

        val notification = NotificationCompat.Builder(context, NOTIFICATION_CHANNEL_ID).apply {
            setSmallIcon(R.drawable.baseline_alarm_add_24)
            setContentTitle(title)
            setContentText(description)
            setPriority(NotificationCompat.PRIORITY_HIGH)
            setCategory(NotificationCompat.CATEGORY_ALARM)
            setOngoing(true)

            setFullScreenIntent(openAlarmChallengeScreenIntent, true)
        }.build()
        
        startForeground(id, notification)

    }


    private fun createAlarmChallengeScreenIntent(
        context: Context,
        time: String,
        id: Int,
    ): PendingIntent {
        val intent = Intent(context, AlarmChallengeScreen::class.java).apply {
            putExtra(EXTRA_TIME, time)
            putExtra(EXTRA_ID, id)
        }

        val requestCode = "openAlarmChallengeScreen$time${id}".hashCode()

        return PendingIntent.getActivity(context, requestCode, intent, PendingIntent.FLAG_MUTABLE)
    }


}

问题可能出在 startForeground(id, notification) 上。即使我使用不同的通知 ID，问题仍然存在，当前通知被取消并显示新通知。

Answer 1

要显示多个通知而不替换旧通知，您需要提供唯一的 ID。

val uniqueId = System.currentTimeMillis().toInt()

val notification = NotificationCompat.Builder(context, NOTIFICATION_CHANNEL_ID).apply {
    setSmallIcon(R.drawable.baseline_alarm_add_24)
    setContentTitle(title)
    setContentText(description)
    setPriority(NotificationCompat.PRIORITY_HIGH)
    setCategory(NotificationCompat.CATEGORY_ALARM)
    setOngoing(true)
    setFullScreenIntent(openAlarmChallengeScreenIntent, true)
}.build()

startForeground(uniqueId, notification)