Elevation on Android Lollipop not working

I am trying to make use of the elevation property in the latest Android Lollipop preview release. I set the targetSdk to 21 and the theme to Material. Next i added a background shape to a TextView and set the elevation to 8dp but the TextView is not showing any signs of a shadow. That is on a Nexus7 running the Lollipop preview. Is there anything else i have to consider?

Here is the layout:

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

  <TextView
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:background="@drawable/rect"
      android:text="hallo world"
      android:padding="8dp"
      android:elevation="8dp" />

</LinearLayout>

This is the background drawable:

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
     android:shape="rectangle">
    <solid android:color="#7d0073ff" />
    <corners android:radius="16dp" />
</shape>

Here is the TextView:

For some reason if you set a solid color with a transparency, the elevation shadow does not show up.

In your example, I changed #7d0073ff to #0073ff and I got a shadow.

This is probably a bug, as in their documentation it gives a similar example using a translucent background color.

After going through the docs again, I finally found the solution.

Just add card_view:cardUseCompatPadding="true" to your CardView and shadows will appear on Lollipop devices.

What happens is, the content area in a CardView take different sizes on pre-lollipop and lollipop devices. So in lollipop devices the shadow is actually covered by the card so its not visible. By adding this attribute the content area remains the same across all devices and the shadow becomes visible.

My xml code is like :

<android.support.v7.widget.CardView
    android:id="@+id/media_card_view"
    android:layout_width="match_parent"
    android:layout_height="130dp"
    card_view:cardBackgroundColor="@android:color/white"
    card_view:cardElevation="2sp"
    card_view:cardUseCompatPadding="true"
    >
...
</android.support.v7.widget.CardView>

ADDING android:elevation shadow to an ImageView:

android:clipToPadding="false"
+
android:outlineProvider="bounds"
+
android:elevation="2dp"

I was also having this problem, and as it turns out, you need to turn hardware acceleration on in the android manifest

<application
  ...
  android:hardwareAccelerated="true">