<?xml version="1.0" encoding="utf-8" ?>   <selector xmlns:android="http://schemas.android.com/apk/res/android"> <!-- 默认时的背景图片-->    <item android:drawable="@drawable/pic1" />    <!-- 没有焦点时的背景图片 -->    <item android:state_window_focused="false"           android:drawable="@drawable/pic1" />   <!-- 非触摸模式下获得焦点并单击时的背景图片 -->    <item android:state_focused="true" android:state_pressed="true"   android:drawable= "@drawable/pic2" /> <!-- 触摸模式下单击时的背景图片-->  <item android:state_focused="false" android:state_pressed="true"   android:drawable="@drawable/pic3" />  <!--选中时的图片背景-->    <item android:state_selected="true"   android:drawable="@drawable/pic4" />   <!--获得焦点时的图片背景-->    <item android:state_focused="true"   android:drawable="@drawable/pic5" />   </selector>