SimpleHttpServer.cs

using System;
using System.Net;
using System.Text;
using System.Threading;

namespace SimpleHttp
{
    // reference: https://www.codehosting.net/blog/BlogEngine/post/Simple-C-Web-Server
    class SimpleHttpServer
    {
        private readonly HttpListener _server = new HttpListener();
        private readonly Func<HttpListenerRequest, string> _respondMethod;

        public SimpleHttpServer(string[] prefixes, Func<HttpListenerRequest, string> method)
        {
            if (!HttpListener.IsSupported)
                throw new NotSupportedException("HttpListener not supported.");

            if (prefixes == null || prefixes.Length == 0)
                throw new ArgumentException("Prefixs");

            _respondMethod = method ?? throw new ArgumentNullException("method");

            foreach (var s in prefixes)
                _server.Prefixes.Add(s);

            _server.Start();
        }

        public SimpleHttpServer(Func<HttpListenerRequest, string> method, params string[] prefixes) : this(prefixes, method) { }

        public void Run()
        {
            while (_server.IsListening)
            {
                ThreadPool.QueueUserWorkItem((c) => 
                {
                    var ctx = c as HttpListenerContext;
                    try
                    {
                        var resp = _respondMethod(ctx.Request);
                        var buf = Encoding.UTF8.GetBytes(resp);
                        ctx.Response.ContentLength64 = buf.Length;
                        ctx.Response.OutputStream.Write(buf, 0, buf.Length);
                    }
                    catch (Exception ex)
                    {
                        Console.WriteLine(ex.ToString());
                    }
                    finally
                    {
                        ctx.Response.OutputStream.Close();
                    }
                }, _server.GetContext());
            }
        }

        public void Stop()
        {
            _server.Stop(); // pause
            _server.Close();// pending request not completed
        }
    }
}