Q: Change notification icon in Android Studio

Question

I configured the application icon (Image 1), but the notification icon (Notification sent via Firebase) shows a gray rectangle (Image 2). What is the procedure for changing the notification icon image (Image 2) via Android Studio 2.3 or via script?

Manifest

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.studioshow.studioshow">
<uses-permission android:name="android.permission.INTERNET" />
<application
    android:allowBackup="true"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:roundIcon="@mipmap/ic_launcher"
    android:supportsRtl="true"
    android:theme="@style/AppTheme">

    <activity android:name=".MainActivity">

        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />


        </intent-filter>
    </activity>
</application>

Answer 1

EDIT: My answer is not relevant: I did not read about the Firebase messaging part.

---

Simply use setSmallIcon(int), provided by NotificationBuilder and its Compat counterpart.

You can retrieve the icon from your resource folder by passing, e.g. R.drawable.my_icon as parameter.

Answer 2

In manifest file. Set meta data. Following code is my case.

   <application
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@android:style/Theme.NoTitleBar"  >
        <activity
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

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


        <service
            android:name=".MyFirebaseMessagingService">
            <intent-filter>
                <action android:name="com.google.firebase.MESSAGING_EVENT"/>
            </intent-filter>
        </service>

        <meta-data
            android:name="com.google.firebase.messaging.default_notification_icon"
            android:resource="@drawable/ic_launcher" />
        <meta-data
            android:name="com.google.firebase.messaging.default_notification_color"
            android:resource="@color/whitechoke" />

    </application>