android 选择器selector

<?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/button" /> -->
<!-- 没有焦点时的背景图片 -->
<item android:state_window_focused="false" android:drawable="@drawable/button" />
<!-- 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/header" /> -->
<!-- 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/button_click" />
<!--选中时的图片背景 -->
<!-- <item android:state_selected="true" android:drawable="@drawable/left" /> -->
<!--获得焦点时的图片背景 -->
<!-- <item android:state_focused="true" android:drawable="@drawable/right" /> -->
</selector>