<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:state_selected="true" android:drawable="@drawable/bg_state_2"/>

    <!-- 未选中状态：深色透明背景 -->
    <item android:drawable="@drawable/bg_state_1" />

</selector>