Csharp 从目录中获取文件的异步函数未按预期工作

I'm working on a Blazor project.
I try to make a asynchronous function to get ".avi" and ".mkv" files from directory. But When I try to access the page instead of having my "Loading..." message, it takes times until I got all the result in one time.

以下是我的服务代码:

namespace FilesScanner
{
    public class FilesScannerService
    {
        public async Task<IEnumerable<FileInfo>> GetFilesAsync(string path,
            EnumerationOptions options, string[] extensions)
        {
            DirectoryInfo dir = new(path);

            return await Task.Run(() => extensions.SelectMany(x => dir.EnumerateFiles(x, options)
                .Where(f => !f.Attributes.HasFlag(FileAttributes.Hidden))));
        }
    }
}

下面是Blazor页面的代码，我在其中调用了上面的函数:

using FilesScanner;
using Microsoft.AspNetCore.Components;

namespace MovieLibrary.Pages
{
    public partial class Files
    {
        [Inject] private FilesScannerService _scannerService { get; set; }

        public IEnumerable<FileInfo> FilesInfos { get; set; }

        protected override async Task OnInitializedAsync()
        {
            string path = @"C:\Users\username\Videos";

            string[] extensions =
            {
                "*.avi",
                "*.mkv"
            };

            EnumerationOptions opts = new()
            {
                IgnoreInaccessible = true,
                RecurseSubdirectories = true
            };

            FilesInfos = await _scannerService.GetFilesAsync(path, opts ,extensions);
        }
    }
}

最后是显示结果的代码:

@page "/files"
@using System.IO;
<h3>Movies</h3>

@if (FilesInfos is not null)
{
    try
    {
        int i = 1;
        foreach (FileInfo file in FilesInfos)
        {
            <p><span style="font-weight:700">@i :</span> @Path.GetFileNameWithoutExtension(@file.Name)</p>
            i++;
        }
    }
    catch (UnauthorizedAccessException ex)
    {
        <p>@ex.Message</p>
    }
}
else
{
    <h2>LOADING...</h2>
}

我是不是误解了异步函数的某些方面？