title: Remove shadow in Button
body: <p>I created a button, set the background to <code>@null</code>, but shadow is still there. </p>
  
  <p>How can I remove the shadow?</p>
  
  <pre><code>&lt;Button
          android:id="@+id/button1"
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:textAllCaps="false"
          android:background="@null"
          android:text="Random" /&gt;
  </code></pre>