<?xml version="1.0" encoding="utf-8"?><!-- 默认按钮样式 -->
<selector xmlns:android="http://schemas.android.com/apk/res/android">

    <!-- 禁用状态 -->
<!--    <item android:state_enabled="false" android:drawable="@drawable/btn_update_select_bg"/>-->

    <!-- 按压状态 -->
    <item android:drawable="@drawable/btn_update_select_bg" android:state_pressed="true" />

    <!-- 焦点状态 -->
    <item android:drawable="@drawable/btn_update_select_bg" android:state_focused="true" />

    <!-- 默认状态 -->
    <item android:drawable="@drawable/btn_update_bg" />

</selector>