Lost press effect of the button when set gradient background by shape
<p>Usually, there's a bit effect when we press a button. But when I set gradient background for a button by creating a shape border.xml:</p>

<pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
&lt;shape
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle"&gt;
    &lt;stroke android:width="1px" android:color="#cccccc" /&gt;
    &lt;corners android:radius="6px" /&gt;
    &lt;gradient
      android:startColor="#d8d8d8"
      android:endColor="#f9f2f9"
      android:angle="90" /&gt; 
&lt;/shape&gt;
</code></pre>

<p>and button:</p>

<pre><code>        &lt;Button
        android:id="@+id/visibility"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:gravity="center_vertical"
        android:drawableLeft="@drawable/idle"
        android:singleLine="true"           
        android:padding="5px"
        android:textSize="14px"
        android:textColor="#444444"
        android:textStyle="bold"
        android:typeface="sans"
        android:layout_marginLeft="5px"
        android:layout_marginRight="5px"    
        android:background="@drawable/border"
        android:clickable="true"&gt;
    &lt;/Button&gt;
</code></pre>

<p>the effect when press the button is lost, the button now is just like a textview, nothing is changed when I click on it.
But if I delete this line in button, everything's ok: </p>

<pre><code>android:background="@drawable/border"
</code></pre>

<p>So any solutions to don't be lost the effect when press the button, or any solutions to make a button has border and gradient background without use shape?
Thanks!</p>
