<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android"
    android:interpolator="@android:anim/decelerate_interpolator"
    android:zAdjustment="top">
    <scale android:fromXScale="1.0" android:toXScale=".5"
        android:fromYScale="1.0" android:toYScale=".5"
        android:pivotX="50%p" android:pivotY="50%p"
        android:duration="300" />
    <!-- 系统内置的动画持续时间
    android:duration="@android:integer/config_mediumAnimTime"
    -->
    <alpha android:fromAlpha="1.0" android:toAlpha="0"
        android:duration="300"/>
</set>