Develop Reference

No ripples for MaterialCardView

Are there no ripples on the new MaterialCardView?
I used CardView with android:clickable="true" and android:foreground="?android:attr/selectableItemBackground" which worked fine but with the new MaterialCardView there are no ripples at all 😰.
Other Views etc. keep working but I want my card to be clickable (with ripple as feedback).

This is a bug with MaterialCardView. It's overriding the foreground after it's created. I've filled a bug. It should be fixed to show a ripple if the card is clickable without needing to set the foreground.
If you can't wait for a fix you could use CardView from the support lib, or you could change your code to set the foreground drawable after the CardView has been inflated, or we would gladly accept a pull request! Relevant code at: https://github.com/material-components/material-components-android/blob/master/lib/java/com/google/android/material/card/MaterialCardView.java. It can probably use https://github.com/material-components/material-components-android/blob/master/lib/java/com/google/android/material/ripple/RippleUtils.java and a RippleDrawable for SDK >= 21.

In my case, It worked after adding android:clickable="true", android:focusable="true" and app:rippleColor="#cfd8dc" in XML file.
<com.google.android.material.card.MaterialCardView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:clickable="true"
android:focusable="true"
app:rippleColor="#cfd8dc">

Ripple effect is working now, but only if you add an OnClickListener on the CardView

Gray horizontal line pre lollipop cardview on bottom

I am trying to get rid of this gray line on my cardview
I am using a color with a bit of transparency - #40B6F2FC
here is my code
<android.support.v7.widget.CardView
android:id="#+id/cardView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:dividerHeight="0px"
android:divider="#null"
app:cardPreventCornerOverlap="false"
app:cardBackgroundColor="#color/sky_colorBlue_20_percent"
app:cardCornerRadius="2dp"
app:cardElevation="2dp"
app:cardMaxElevation="2dp"
app:cardUseCompatPadding="true">
Followed the answer of this question https://stackoverflow.com/a/18734605/1599611 but still didnt work.
Is there a way to get rid of this grayline without setting the elevation to zero and using a color with transparency added?

Base from this tracker
https://issuetracker.google.com/issues/37008169
Status: Won't Fix (Intended Behavior) CardView does not support
transparency for its background. This is due to limitations of drawing
shadows using canvas api.

Card view shadow is not showing

This is my card_view. I have mentioned card_view:cardElevation.
But still shadow is not showing.
I have searched many links. Everywhere they have mentioned to use card_view:cardElevation.
<android.support.v7.widget.CardView
android:id="#+id/card_view"
xmlns:card_view="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="wrap_content"
card_view:cardBackgroundColor="#color/white"
card_view:cardCornerRadius="4dp"
card_view:cardElevation="5dp"
card_view:cardUseCompatPadding="true"
app:cardPreventCornerOverlap="false">
</android.support.v7.widget.CardView>
Can you tell what I am missing here?

Read https://developer.android.com/training/material/lists-cards.html
To create a card with a shadow, use the card_view:cardElevation
attribute. CardView uses real elevation and dynamic shadows on Android
5.0 (API level 21) and above and falls back to a programmatic shadow implementation on earlier versions. For more information, see
Maintaining
Compatibility.
UPDATE
try adding margin to card if you want to see shadow
check https://developer.android.com/reference/android/support/v7/widget/CardView.html

Set the following attribute in your cardview
card_view:cardUseCompatPadding = "true"
card_view:cardElevation = "5dp"

cardElevation not showing shadows on Lollipop

I've checked a whole bunch of answers here, and still no dice. Android Studio preview shows the shadow, but not the 5.1.1 Nexus 7.
Here's my XML
<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.CardView
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:card_view="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="wrap_content"
card_view:cardCornerRadius="4dp"
card_view:cardUseCompatPadding="true"
card_view:cardElevation="20sp"
card_view:cardPreventCornerOverlap="true"
android:layout_margin="6dp"
>
So I've used cardUseCompatPadding (also here), checked the documentation, made sure the card has a margin .... no dice.
I posted the total XML file over at https://gist.github.com/tigerhawkvok/0ca3d1f402afa29642d5 .
Help?

On device, shadows are drawn only if the view background is not null and not transparent. However, a bug in the layout preview in Android Studio prevents it from checking the background before drawing the shadow. Hence you see the difference.
But you shouldn't really need to set the elevation on card view, since it creates its own shadow or sets the elevation depending on the platform version.

Strange CardView behaviour

I'm trying to implement simple cardview with semi-transparent background.
<android.support.v7.widget.CardView
android:id="#+id/card_view"
app:cardBackgroundColor="#33FFFFFF"
app:cardCornerRadius="4dp"
android:foreground="#33FFFFFF"
android:padding="20dp"
android:layout_width="match_parent"
android:layout_height="100dp">
......
</android.support.v7.widget.CardView>
And this is the result in L and preL
android L: (Nexus 5)
Pre L:
Any idea how to fix the pre L to look like L ?
As you can see there are too many borders/strokes surrounding the card.
I'm can guess it relates to shadows and stuff...
Thanks.

Look like it's a known defect in google forums
Thanks to #benhylau for providing implementation for cardview with alpha here
There no possible to color cardview background with #__FFFFF as it ignores the transparency values. need to work with alpha attribute