Ripple effect on Android Lollipop CardView

Question

You should add following to CardView:

android:foreground="?android:attr/selectableItemBackground"
android:clickable="true"

Add these two line code into your xml view to give ripple effect on your cardView.

android:clickable="true"
android:foreground="?android:attr/selectableItemBackground"

I managed to get the ripple effect on the cardview by :

<android.support.v7.widget.CardView 
    xmlns:card_view="http://schemas.android.com/apk/res-auto" 
    android:clickable="true" 
    android:foreground="@drawable/custom_bg"/>

and for the custom_bg that you can see in above code, you have to define a xml file for both lollipop(in drawable-v21 package) and pre-lollipop(in drawable package) devices. for custom_bg in drawable-v21 package the code is:

<ripple 
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:color="?android:attr/colorControlHighlight">
<item
    android:id="@android:id/mask"
    android:drawable="@android:color/white"/>
</ripple>

for custom_bg in the drawable package, code is:

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">

<item android:state_pressed="true">
    <shape>
        <solid android:color="@color/colorHighlight"></solid>
    </shape>
</item>
<item>
    <shape>
        <solid android:color="@color/navigation_drawer_background"></solid>
    </shape>
</item>
</selector>

so on pre-lollipop devices you will have a solid click effect and on lollipop devices you will have a ripple effect on the cardview.

The ripple effect was omitted in the appcompat support library which is what you're using. If you want to see the ripple use the Android L version and test it on an Android L device. Per the AppCompat v7 site:

"Why are there no ripples on pre-Lollipop? A lot of what allows RippleDrawable to run smoothly is Android 5.0’s new RenderThread. To optimize for performance on previous versions of Android, we've left RippleDrawable out for now."

Check out this link here for more info

If the app minSdkVersion which you are working is level 9, you can use:

android:foreground="?selectableItemBackground"
android:clickable="true"

Instead, starting from level 11, you use:

android:foreground="?android:attr/selectableItemBackground"
android:clickable="true"

From documentation:

clickable - Defines whether this view reacts to click events. Must be a boolean value, either "true" or "false".

foreground - Defines the drawable to draw over the content. This can be used as an overlay. The foreground drawable participates in the padding of the content if the gravity is set to fill.

Use Material Cardview instead, it extends Cardview and provides multiple new features including default clickable effect :

<com.google.android.material.card.MaterialCardView>

...

</com.google.android.material.card.MaterialCardView>

Dependency (It can be used up to API 14 to support older device):

implementation 'com.google.android.material:material:1.0.0'