<?xml version="1.0" encoding="utf-8"?> <objectAnimator xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:aapt="http://schemas.android.com/aapt" android:interpolator="@android:anim/linear_interpolator" android:duration="150" android:valueFrom="0" android:valueTo="1" android:propertyName="alpha"/>Download file