<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="rectangle">
<gradient
android:startColor="#FF2200"
android:endColor="#1E7650"
android:angle="-90"/>
</shape>
原文：http://www.cnblogs.com/jiezzy/p/5058850.html