From what I understand, early in the preview stage there seemed to be no way to set elevation in XML only on CardViews without a hack in Java. Now that the offi
CardView
If you have this line
android:hardwareAccelerated="false"
in manifest application tag your shadows were not displayed. try to remove this line
or use
android:hardwareAccelerated="true"
This worked for me! I hope it works for you too :)