translationZ not working in my ConstraintLayout with map fragment

Question

I have a ImageView on a Map frangment which both of them placed in a ConstraintLayout. I set android:translationZ="2dp" and then android:elevation="2dp" for ImageView but still can't see image.

map_main.xml:

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <fragment
        android:id="@+id/mapView"
        android:name="com.google.android.gms.maps.SupportMapFragment"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.0"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        tools:context=".MapsActivity" />

    <ImageView
        android:id="@+id/testImage"
        android:layout_width="64dp"
        android:layout_height="64dp"
        app:layout_constraintBottom_toBottomOf="@+id/mapView"
        app:layout_constraintStart_toStartOf="parent"
        app:srcCompat="@drawable/test"
        android:translationZ="2dp"/>

</androidx.constraintlayout.widget.ConstraintLayout>

The weird thing is, I set an OnClickListener to image and I can click it. It looks like ImageView is there, on the top of map fragment but I can't see it.

How can I send map fragment to back or bring views to front?

Answer 1

Changing app:srcCompat with android:src worked fine. Final xml looks like:

 <?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <fragment
        android:id="@+id/mapView"
        android:name="com.google.android.gms.maps.SupportMapFragment"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.0"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        tools:context=".MapsActivity" />

    <ImageView
        android:id="@+id/testImage"
        android:layout_width="64dp"
        android:layout_height="64dp"
        app:layout_constraintBottom_toBottomOf="@+id/mapView"
        app:layout_constraintStart_toStartOf="parent"
        android:src="@drawable/test"
        android:translationZ="2dp"/>

</androidx.constraintlayout.widget.ConstraintLayout>

Thanks to @mohosyny and @ReazMurshed.