Transparent background on CardView – Android

Setup your CardView to use the cardBackgroundColor attribute to remove color and cardElevation attribute to remove the drop shadow. For example:

<android.support.v7.widget.CardView
    xmlns:card_view="http://schemas.android.com/apk/res-auto"
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/myCardView"
    android:layout_width="match_parent"
    android:layout_height="match_parent" 
    card_view:cardBackgroundColor="@android:color/transparent"
    card_view:cardElevation="0dp"> 

For a full list of supported attributes see here: https://developer.android.com/reference/android/support/v7/widget/CardView.html

If you are using an older API, you will need to call these two functions on your CardView instead:

myCardView.setCardBackgroundColor(Color.TRANSPARENT);
myCardView.setCardElevation(0);