Banyc

public class ConcurrentHashSet<T> : HashSet<T>
{
    public new bool Add(T item)
    {
        lock (this)
        {
            return base.Add(item);
        }
    }
    // ...

Banyc

@page "/upload"
@using System.IO
@using System.Text
@using System.Net.Http.Headers
@using Tewr.Blazor.FileReader
@using Microsoft.Extensions.Configuration

@inject HttpClient httpClient
@inject NavigationManager NavigationManager
@inject IFileReaderService fileReaderService