Как реализовать асинхронное прослушивание HttpListener C#?

HttpListener listener = new HttpListener();
        StringBuilder log = new StringBuilder();
        string path;
        private async void button1_Click(object sender, EventArgs e)
        {
            listener.Prefixes.Add("http://localhost:8080/");

            listener.Start();
            //listener.AuthenticationSchemes = AuthenticationSchemes.Anonymous;
            if (listener.IsListening)
            {
                button1.Enabled = false;
                log.Append("Start server...");
                richTextBox1.Text= log.ToString();
            }

            while (true)
                try
                {
                    HttpListenerContext request = listener.GetContext();
                    ThreadPool.QueueUserWorkItem(ProcessRequest, request);
                }
                catch (HttpListenerException) { break; }
                catch (InvalidOperationException) { break; }
        }