Hub file from SignalR tutorial at http://www.antoinedahan.com/blog/SignalRAzureTutorial/

ExampleHub.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using Microsoft.AspNet.SignalR;

namespace SignalRExample.Hubs
{
    public class ExampleHub : Hub
    {
        /* C# function AddComment(string) is called from jquery in index.html */
        public void AddCommentToServer(string commentToAdd)
        {
            // Call back to AddNewComment jquery function for ALL clients
            // (sends the parameter sent by each client to this function to all clients)
            Clients.All.AddCommentLocal(commentToAdd);
        }
    }
}