I am working in signal r mvc .. and Connection through hub not created my hub code is
public class ChatHub : Hub
{
    private readonly static ConnectionMapping<string> _connections =
        new ConnectionMapping<string>();
    public void SendChatMessage(string who)
    {
        string name = Context.User.Identity.Name;
        Clients.User(who).addChatMessage();
    }
    public override Task OnConnected()
    {
        string name = Context.User.Identity.Name;
        _connections.Add(name, Context.ConnectionId);
         Debug.Write("Shubham Conected");
        return base.OnConnected();
    }
    public override Task OnDisconnected(bool stopCalled)
    {
        string name = Context.User.Identity.Name;
        _connections.Remove(name, Context.ConnectionId);
        Debug.Write("Shubham now Disconnected");
        return base.OnDisconnected(stopCalled);
    }
    public override Task OnReconnected()
    {
        string name = Context.User.Identity.Name;
        if (!_connections.GetConnections(name).Contains(Context.ConnectionId))
        {
            _connections.Add(name, Context.ConnectionId);
        }
        Debug.Write("Shubham Reconnected");
        return base.OnReconnected();
    }
    public void SendChatMessage(string who, string message)
    {
        string name = Context.User.Identity.Name;
        Debug.Write("Shubham inside the send");
        Clients.Group(who).addChatMessage(name + ": " + message);
    }
} 
When I execute it in debug mode in visual studio 2013, it throws exception in
Context.User.Identity.Name; null reference exception.
I don't know how to solve this problem. 
When I use this statement in my controller than this code returns the userId. 
 
     
    