帧动画布局文件 animation-list

<?xml version="1.0" encoding="utf-8"?>
<animation-list xmlns:android="http://schemas.android.com/apk/res/android">
    android:oneshot="true"
    <item android:drawable="@mipmap/bb" android:duration="200"></item>
    <item android:drawable="@mipmap/cc" android:duration="200"></item>
    <item android:drawable="@mipmap/dd" android:duration="200"></item>
    <item android:drawable="@mipmap/ee" android:duration="200"></item>
</animation-list>

背景选择器

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