Call specific client from SignalR

See the docs for the latest:

Persistent connections - https://github.com/SignalR/SignalR/wiki/PersistentConnection

Hubs - http://www.asp.net/signalr/overview/guide-to-the-api/hubs-api-guide-server

$('#sendmessage').click(function () {
    // Call the Send method on the hub. 
    chat.server.send($('#displayname').val(), $('#message').val(), $.connection.hub.id);
    // Clear text box and reset focus for next comment. 
    $('#message').val('').focus();
});

at server side send the id of the client and response to that id

  public void Send ( string name , string message , string connID )
  {
        Clients.Client(connID).broadcastMessage(name , message);
  }

Every time you send a request to the hub server, your request will have a different connection id, so, I added a static hash table that contains a username- which is not changing continuously, and a connection id fro the signal r,every time you connect, the connection id will be updated

 $.connection.hub.start().done(function () {
   chat.server.registerConId($('#displayname').val());
 });

and in the server code:

public class ChatHub : Hub
{
    private static Hashtable htUsers_ConIds = new Hashtable(20);
    public void registerConId(string userID)
    {
        if(htUsers_ConIds.ContainsKey(userID))
            htUsers_ConIds[userID] = Context.ConnectionId;
        else
            htUsers_ConIds.Add(userID, Context.ConnectionId);
    }
}

when you want to send a message to specific id

 Clients.Client(Context.ConnectionId).onMessage(
               new Message{From = e.Message.From, Body = e.Message.Body}
               );

If the specific user actually is the caller it self, you can use:

Clients.Caller.myJavaScriptClientFunction();