.NET MAUI Android 13（API33）权限请求弹窗不显示问题求助

我在使用.NET MAUI开发适配Android 13（API 33）的应用时，遇到权限相关问题：请求用户授权的弹窗无法显示。查阅网上相关帖子后未找到解决办法，附上我的代码，希望能得到帮助。

AppShell代码 #

private void AppShell_Loaded(object sender, EventArgs e)
{
    try
    {
        ProcessInit();
    }
    catch (Exception ex)
    {
        throw new Exception(ex.Message);
    }
}

private async Task ProcessInit()
{
    if (!RequestPermision.RequestStoragePermissionsBool())
    {
        await Task.Run(async () =>
        {
            await RequestPermision.RequestStoragePermissions();
        });
    }
}

权限相关代码 #

适配Android 12及以下版本的权限类 #

public class ReadWriteStoragePermsLower12 : Permissions.BasePlatformPermission
{
    public override (string androidPermission, bool isRuntime)[] RequiredPermissions =>
        new List<(string androidPermission, bool isRuntime)>
        {
            ("android.permission.READ_EXTERNAL_STORAGE", true),
            ("android.permission.WRITE_EXTERNAL_STORAGE", true),
            ("android.permission.INTERNET", true)
        }.ToArray();
}

适配Android 13及以上版本的权限类 #

public class ReadWriteStoragePerms : Permissions.BasePlatformPermission
{
    public override (string androidPermission, bool isRuntime)[] RequiredPermissions =>
        new List<(string androidPermission, bool isRuntime)>
        {
            ("android.permission.READ_MEDIA_IMAGES", true),
            ("android.permission.READ_MEDIA_AUDIO", true),
            ("android.permission.READ_MEDIA_VIDEO", true),
            ("android.permission.INTERNET", true)
        }.ToArray();
}

权限状态检查与请求类 #

public class RequestPermision
{
    private static IAppServices _services;

    public RequestPermision(IAppServices pServices)
    {
        _services = pServices;
    }

    public static async Task RequestStoragePermissions()
    {
        if (DeviceInfo.Platform != DevicePlatform.Android)
            return;

        var status = PermissionStatus.Unknown;

        if (DeviceInfo.Version.Major >= 13)
        {
            status = await Permissions.CheckStatusAsync<ReadWriteStoragePerms>();

            if (status == PermissionStatus.Granted)
            {
                _services?.CallServiceListFolder();
                return;
            }

            if (Permissions.ShouldShowRationale<ReadWriteStoragePerms>())
            {
                await AlertPermissionDenited();
            }

            status = await Permissions.RequestAsync<ReadWriteStoragePerms>();

            if (status != PermissionStatus.Granted)
            {
                await AlertPermissionDenited();
            }
        }
        else
        {
            status = await Permissions.CheckStatusAsync<ReadWriteStoragePermsLower12>();

            if (status == PermissionStatus.Granted)
            {
                _services?.CallServiceListFolder();
                return;
            }

            if (Permissions.ShouldShowRationale<ReadWriteStoragePermsLower12>())
            {
                await AlertPermissionDenited();
            }

            status = await Permissions.RequestAsync<ReadWriteStoragePermsLower12>();

            if (status != PermissionStatus.Granted)
            {
                await AlertPermissionDenited();
            }
        }
    }

    private static async Task AlertPermissionDenited()
    {
        await App.Current.MainPage.DisplayAlert("Needs permissions", "Permissions are required for the app to access system folders and files to perform conversions!", "OK");
    }

    public static async Task<bool> RequestStoragePermissionsBool()
    {
        if (DeviceInfo.Platform != DevicePlatform.Android)
            return false;

        var status = PermissionStatus.Unknown;
        bool granted = false;

        if (DeviceInfo.Version.Major >= 13)
        {
            status = await Permissions.CheckStatusAsync<ReadWriteStoragePerms>();

            if (status == PermissionStatus.Granted)
                granted = true;
        }
        else
        {
            status = await Permissions.CheckStatusAsync<ReadWriteStoragePermsLower12>();

            if (status == PermissionStatus.Granted)
                granted = true;
        }

        return granted;
    }
}

AndroidManifest.xml配置 #

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android">
    <application android:allowBackup="true" android:icon="@mipmap/appicon" android:supportsRtl="true"></application>
    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" android:maxSdkVersion="32" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" android:maxSdkVersion="32" />
    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.READ_MEDIA_IMAGES" />
    <uses-permission android:name="android.permission.READ_MEDIA_VIDEO" />
    <uses-permission android:name="android.permission.READ_MEDIA_AUDIO" />
    <uses-sdk android:minSdkVersion="21" android:targetSdkVersion="32" />
</manifest>

内容的提问来源于stack exchange，提问作者Leonardo Silva