<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
    <!-- 边框颜色值 -->
    <item>
        <shape>
            <solid android:color="@color/red" /><!--下划线颜色-->
        </shape>
    </item>
    <item android:bottom="1dp"> <!--下划线厚度-->
        <shape>
            <solid android:color="@color/white" /><!--背景色 不能透明否则会显示上面的下划线颜色-->
        </shape>
    </item>
</layer-list>