Android, Designing custom Button (gradient and animation)

In my application I want to apply gradient to Button. I have written following code and the result is perfect.

<?xml version="1.0" encoding="utf-8"?>

<layer-list 
xmlns:android="http://schemas.android.com/apk/res/android">
    <item>
        <shape>
            <padding 
                android:left="1dp"
                android:top="1dp"
                android:right="1dp"
                android:bottom="1dp"/>

            <solid 
            android:color="#FF000000"/>

        </shape>
    </item>

    <item>
        <shape>
            <padding 
            android:left="5dp"
            android:top="5dp"
            android:right="5dp"
            android:bottom="5dp"/>

            <gradient 
            android:startColor="#FFB0B0B0"
            android:centerColor="#FFFFFFFF"
            android:endColor="#FFB0B0B0"
            android:angle="315"/>

            <corners 
            android:radius="3dp"/>
        </shape>
    </item>


</layer-list>

But my problem is, when I click on this button I have no effect or animation such as original one. Therefor, I want to add some effect on it t开发者_运维百科hat when user clicks on it the button becomes bigger and when released the key, the button comeback to its situation.

guide me please. thanks :)

This is for only background of button but you have not specified anything for different events like click, hover, etc.

For that you have to create another set of styles and set them in selector as in my previous answer and make that selector as background of your button