Android-启动页“android:windowBackground”变型？

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:drawable="@android:color/white" />
    <item>
        <bitmap
            android:gravity="bottom"
            android:scaleType="centerCrop"
            android:src="@drawable/bg_splash"
            android:tileMode="disabled" />
    item>
layer-list>

    <style name="main_splash_activity_style" parent="Theme.AppCompat">
        <item name="android:windowBackground">@drawable/main_bitmap_splash_bgitem>
        <item name="android:windowFullscreen">trueitem>
        
        
        
        
        <item name="windowNoTitle">trueitem>
    style>

<activity
            android:name=".activity.SplashActivity"
            android:screenOrientation="portrait"
            android:theme="@style/main_splash_activity_style">
activity>