未显示Android通知，但没有错误[重复]

Question

此问题已经在这里有了答案：

Notifications do not work on Android Oreo [duplicate] （1个答案）

Notification not showing in Oreo （22个答案）

关闭4分钟前。

我正在尝试向用户显示通知，但是某些操作无效。没有记录错误消息，并且应用程序继续运行。我正在从我的应用程序的主活动中调用此代码。

    val notificationId = buildNotificationId(messageId)
    val builder: NotificationCompat.Builder = NotificationCompat.Builder(this,"123")
    val mNotificationManager = getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager
    val pendingIntent = Intent(this, MainPage::class.java)
    val notifyPendingIntent = PendingIntent.getActivity(this, 0, pendingIntent, PendingIntent.FLAG_UPDATE_CURRENT)
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
        pendingIntent.flags = Intent.FLAG_ACTIVITY_NEW_TASK or Intent.FLAG_ACTIVITY_CLEAR_TASK
        builder.setSmallIcon(R.drawable.icon)
            .setLargeIcon(BitmapFactory.decodeResource(applicationContext.resources, R.drawable.icon))
            .setSound(RingtoneManager.getDefaultUri(RingtoneManager.TYPE_NOTIFICATION))
            .setContentTitle(title)
            .setAutoCancel(true)
            .setStyle(NotificationCompat.BigTextStyle().bigText(message))
            .setOnlyAlertOnce(true)
        builder.setContentIntent(notifyPendingIntent)
        mNotificationManager.notify(notificationId, builder.build())
    }

Answer 1

谢谢，我忘了创建频道！