Android push notification in notification center is an grey icon

Question

I created an app that should send out an push notification when you press a button. It does but there is an issue: The icon in the notification center is grayed out. but when I'm in an app and look in the top left corner the icon is there.

My Android version is 9 so this isn't the android lollipop issue

Some pictures:

Push notification in notification center:

Push notification in apps:

This person had the same issue and it was resolved by putting a transparent/white version from the image in the res folder I did it (and it's still there so you can check if I did it right) but it didn't work for me:

Why is my smallIcon for Notifications always greyed out?

and I can't find the exact question but someone also suggested to put a line of code in the Manifest file (which is also still there which you can check out if I did it right):

<meta-data android:name="com.google.firebase.messaging.default_notification_icon"
            android:resource="@mipmap/whatsapp_icon" />

MainActivity.java:

package Package name that I chose;

import android.app.Notification;
import android.app.NotificationChannel;
import android.app.NotificationManager;
import android.app.PendingIntent;
import android.content.Context;
import android.content.Intent;
import android.graphics.Color;
import android.support.v4.app.NotificationCompat;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

    public void onClick(View view) {
        NotificationManager NM;
        Notification Note;

        NM = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);

        Intent intent = new Intent("com.rj.notitfications.SECACTIVITY");

        PendingIntent pendingIntent = PendingIntent.getActivity(MainActivity.this, 1, intent, 0);

        String CHANNEL_ID = "my_channel_01";
        CharSequence name = "my_channel";
        String Description = "This is my channel";
        int importance = NotificationManager.IMPORTANCE_HIGH;
        NotificationChannel mChannel = new NotificationChannel(CHANNEL_ID, name, importance);
        mChannel.setDescription(Description);
        mChannel.enableLights(true);
        mChannel.setLightColor(Color.RED);
        mChannel.enableVibration(true);
        mChannel.setVibrationPattern(new long[]{100, 200, 300, 400, 500, 400, 300, 200, 400});
        mChannel.setShowBadge(true);
        NM.createNotificationChannel(mChannel);

        Notification.Builder builder = new Notification.Builder(MainActivity.this, CHANNEL_ID);

        builder.setAutoCancel(false);
        builder.setTicker("this is ticker text");
        builder.setContentTitle("WhatsApp Notification");
        builder.setContentText("You have a new message");
        builder.setSmallIcon(R.mipmap.whatsapp_icon);
//        builder.setLargeIcon(R.mipmap.whatsapp_icon_round);
        builder.setContentIntent(pendingIntent);
        builder.setOngoing(false);
        builder.setSubText("This is subtext...");   //API level 16
        builder.setNumber(100);
        builder.build();

        Note = builder.getNotification();
        NM.notify(11, Note);
    }
}

AndroidManifest.xml:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.ste999.whatsapprelay">

    <application
        android:allowBackup="true"
        android:icon="@mipmap/whatsapp_icon"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/whatsapp_icon_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <meta-data android:name="com.google.firebase.messaging.default_notification_icon"
            android:resource="@mipmap/whatsapp_icon" />
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

and here's a link to my res folder

I expect someone can point out my error and make it so that the icon is also there in the notification center instead of a grey circle

Answer 1

Create an asset that only uses white pixels, on a transparent background. It's important to not use any colour other than white.

use link to create notification icon https://romannurik.github.io/AndroidAssetStudio/