1.首页主题

<style name="SplashTheme" parent="Theme.AppCompat.Light.NoActionBar">
        <!-- 欢迎页背景引用刚才写好的 -->
        <item name="android:windowBackground">@drawable/splash</item>
        <item name="android:windowFullscreen">true</item>
        <!-- <item name="android:windowIsTranslucent">true</item> --> <!-- 透明背景不要了 -->
    </style>

2.首页onCreate

override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        val intent = Intent(this,MainActivity::class.java)
        startActivity(intent)
        this.finish()
    }

3.首页的主题背景splash.xml

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
    <!-- 背景颜色 -->
    <item android:drawable="@color/white" />

    <item>
        <!-- 图片 -->
        <bitmap
            android:gravity="center"
            android:src="@drawable/mylogo" />
    </item>
</layer-list>