Kotlin android app is not showing notification

Question

I am building an Android app using Kotlin. I am trying to show notification following this tutorial because I want to support the older versions of the Android as well, https://www.geeksforgeeks.org/notifications-in-kotlin/. But it is not showing the notification.

This is my main activity to show notification

class MainActivity : AppCompatActivity() {

    lateinit var notificationManager: NotificationManager
    lateinit var notificationChannel: NotificationChannel
    lateinit var builder: Notification.Builder
    private val channelId = "i.apps.notifications"
    private val description = "Test notification"
    
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        notificationManager = getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager
        //seedTestData()
        showNotification()


    }

    private fun showNotification() {
        val intent = Intent(this, MessageDetailsActivity::class.java)
        intent.putExtra(MessageDetailsActivity.KEY_MESSAGE, "Test message")

        // FLAG_UPDATE_CURRENT specifies that if a previous
        // PendingIntent already exists, then the current one
        // will update it with the latest intent
        // 0 is the request code, using it later with the
        // same method again will get back the same pending
        // intent for future reference
        // intent passed here is to our afterNotification class
        val pendingIntent = PendingIntent.getActivity(this, 0, intent, PendingIntent.FLAG_UPDATE_CURRENT)

        // RemoteViews are used to use the content of
        // some different layout apart from the current activity layout
        val contentView = RemoteViews(packageName, R.layout.activity_message_details)

        // checking if android version is greater than oreo(API 26) or not
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            notificationChannel = NotificationChannel(channelId, description, NotificationManager.IMPORTANCE_HIGH)
            notificationChannel.enableLights(true)
            notificationChannel.lightColor = Color.GREEN
            notificationChannel.enableVibration(false)
            notificationManager.createNotificationChannel(notificationChannel)

            builder = Notification.Builder(this, channelId)
                    .setContent(contentView)
                    .setSmallIcon(R.drawable.ic_launcher_background)
                    .setLargeIcon(BitmapFactory.decodeResource(this.resources, R.drawable.ic_launcher_background))
                    .setContentIntent(pendingIntent)
        } else {

            builder = Notification.Builder(this)
                    .setContent(contentView)
                    .setSmallIcon(R.drawable.ic_launcher_background)
                    .setLargeIcon(BitmapFactory.decodeResource(this.resources, R.drawable.ic_launcher_background))
                    .setContentIntent(pendingIntent)
        }
        notificationManager.notify(1234, builder.build())
    }

}

This is my activity_message_details.xml file.

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    android:padding="15dp"
    android:orientation="vertical"
    xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent"
    android:layout_height="match_parent">

    <ScrollView
        android:layout_width="match_parent"
        android:layout_height="match_parent">
        <LinearLayout
            android:layout_gravity="center"
            android:gravity="center"
            android:orientation="vertical"
            android:layout_width="match_parent"
            android:layout_height="match_parent">
            <TextView
                android:textColor="@color/primary_text"
                android:id="@+id/message_details_message"
                android:layout_width="match_parent"
                android:layout_height="wrap_content" />

            <androidx.appcompat.widget.AppCompatButton
                android:layout_marginTop="10dp"
                android:background="@color/accent_color"
                android:id="@+id/message_details_share_button"
                android:text="SHARE_MESSAGE"
                android:layout_width="match_parent"
                android:layout_height="wrap_content" />
        </LinearLayout>
    </ScrollView>
</LinearLayout>

When I run the code, it is not showing the notification. What is wrong with my code and how can I fix it?

Answer 1

When I've ran your code I received this error:

Bad notification posted from package com.sandbox.myapplication:
Couldn not inflate contentViewsandroid.view.InflateException:
Binary XML file line #9: Binary XML file line #9:
Error inflating class android.widget.ScrollView

and app crashed.

The problem is that you are using android.widget.ScrollView androidx.appcompat.widget.AppCompatButton in your layout, and this is layout for the RemoteView. For RemoteViews you can use only classes and widgets listed here https://developer.android.com/guide/topics/appwidgets/index.html#CreatingLayout

If you will remove android.widget.ScrollView and androidx.appcompat.widget.AppCompatButton from the layout all should work.

So you need to restruct your layout using classes and widgets from the list.