Flutter 启动画面不适用于 launch_background.xml

我似乎无法显示自己的启动屏幕，每次启动应用程序时，都会显示默认的空白启动屏幕，即使我已在其中设置了所有内容launch_background.xml和其他文件res。我还设置了所有相关的图标drawable and mipmap.

启动背景.xml：

<!-- Modify this file to customize your launch splash screen -->
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
    <item>
        <color android:color="@color/splash" />
    </item>

    <!-- You can insert your own image assets here -->
    <item>
        <bitmap
            android:gravity="center"
            android:src="@drawable/splash_icon" />
    </item>
</layer-list>

样式.xml：

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <!-- Theme applied to the Android Window while the process is starting when the OS's Dark Mode setting is off -->
    <style name="LaunchTheme" parent="@android:style/Theme.Light.NoTitleBar">
        <!-- Show a splash screen on the activity. Automatically removed when
             Flutter draws its first frame -->
        <item name="android:windowBackground">@drawable/launch_background</item>
    </style>
    <!-- Theme applied to the Android Window as soon as the process has started.
         This theme determines the color of the Android Window while your
         Flutter UI initializes, as well as behind your Flutter UI while its
         running.
         
         This Theme is only used starting with V2 of Flutter's Android embedding. -->
    <style name="NormalTheme" parent="@android:style/Theme.Light.NoTitleBar">
        <item name="android:windowBackground">?android:colorBackground</item>
    </style>
</resources>

颜色.xml：

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <color name="ic_launcher_background">#191919</color>
    <color name="splash">#191919</color>
</resources>

<activity>AndroidManifest.xml 中的标签：

<activity
            android:name=".MainActivity"
            android:launchMode="singleTop"
            android:theme="@style/LaunchTheme"
            android:configChanges="orientation|keyboardHidden|keyboard|screenSize|smallestScreenSize|locale|layoutDirection|fontScale|screenLayout|density|uiMode"
            android:hardwareAccelerated="true"
            android:windowSoftInputMode="adjustResize">
            <!-- Specifies an Android theme to apply to this Activity as soon as
                 the Android process has started. This theme is visible to the user
                 while the Flutter UI initializes. After that, this theme continues
                 to determine the Window background behind the Flutter UI. -->
            <meta-data
              android:name="io.flutter.embedding.android.NormalTheme"
              android:resource="@style/LaunchTheme"
              />
            <!-- Displays an Android View that continues showing the launch screen
                 Drawable until Flutter paints its first frame, then this splash
                 screen fades out. A splash screen is useful to avoid any visual
                 gap between the end of Android's launch screen and the painting of
                 Flutter's first frame. -->
            <meta-data
              android:name="io.flutter.embedding.android.SplashScreenDrawable"
              android:resource="@drawable/launch_background"
              />
            <intent-filter>
                <action android:name="android.intent.action.MAIN"/>
                <category android:name="android.intent.category.LAUNCHER"/>
            </intent-filter>
        </activity>

启动屏幕应显示图像和不同的背景颜色，但它只显示默认的空白屏幕。我没有为此使用自定义启动画面。我只想至少改变颜色，但即使这样也不起作用。

还要在drawable-v21/launch_background.xml中进行更改。这将用于 Android API 级别 21 或更高版本。