CardView corners not rounded in an AlertDialog

Question

I'm creating an AlertDialog and the custom layout for that dialog is a CardView (the card is the root of the xml layout):

<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.CardView
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/moreInfoCard"
    android:layout_gravity="center"
    app:cardCornerRadius="12dp"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content">

    //my layout content

</android.support.v7.widget.CardView>

When I show the dialog the card has its corners rounded, but the background of the corners it's not transparent.

How can I solve this issue? Thank you in advance.

Answer 1

call alertDialog.getWindow().setBackgroundDrawableResource(android.R.color.transpare‌​nt); to set the AlertDialog's background to transparent and it will work