Android使用layer-list实现三面边框

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
<item>
<shape>
<solid android:color="#808080"/>
<padding
android:bottom="3.0dip"
android:left="1.0dip"
android:right="1.0dip"
android:top="0.0dip"/>
</shape>
</item>
<item>
<shape>
<solid android:color="#FFFFFF"/>
</shape>
</item>

</layer-list>