<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
    <item>
        <shape android:shape="rectangle">
            <padding android:bottom="1dp" />
            <solid android:color="#00CCCCCC" />

        </shape>
    </item>
    <item>
        <shape android:shape="rectangle">
            <padding android:bottom="1dp" />
            <solid android:color="#10CCCCCC" />

        </shape>
    </item>
    <item>
        <shape android:shape="rectangle">
            <padding android:bottom="1dp" />
            <solid android:color="#50CCCCCC" />

        </shape>
    </item>

    <!-- 中心背景 -->
    <item>
        <shape
            android:shape="rectangle"
            android:useLevel="false">
            <!-- 实心 -->
            <solid android:color="#ffffff" />

            <padding android:bottom="5dp" />
        </shape>
    </item>
</layer-list>