1 window.setAnimationStyle(R.style.PopDownMenu);//在初始化popuwindow后设置popuwindow的样式
2 在styles文件中添加
<!-- popuwindow的样式 -->
<style name="PopDownMenu">
<item name="@android:windowEnterAnimation">@anim/grow_from_topleft_to_bottomright</item>
<item name="@android:windowExitAnimation">@anim/shrink_from_bottomright_to_topleft</item>
</style>
3 在anim文件夹下创建两个文件
文件(1)grow_from_topleft_to_bottomright
<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android">
<scale
android:fromXScale="0.3" android:toXScale="1.0"
android:fromYScale="0.3" android:toYScale="1.0"
android:pivotX="0%" android:pivotY="0%"
android:duration="@android:integer/config_shortAnimTime"
/>
<alpha
android:interpolator="@android:anim/decelerate_interpolator"
android:fromAlpha="0.0" android:toAlpha="1.0"
android:duration="@android:integer/config_shortAnimTime"
/>
</set>
文件(2)shrink_from_bottomright_to_topleft
<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android">
<scale
android:fromXScale="1.0" android:toXScale="0.3"
android:fromYScale="1.0" android:toYScale="0.3"
android:pivotX="0%" android:pivotY="0%"
android:duration="@android:integer/config_shortAnimTime"
/>
<alpha
android:interpolator="@android:anim/accelerate_interpolator"
android:fromAlpha="1.0" android:toAlpha="0.0"
android:duration="@android:integer/config_shortAnimTime"
/>
</set>