Signalr Context null When Calling from Class - asp.net-mvc-5

Question

I've set up Signalr on my MVC 5 website, and most of it is working fine. For example, if I try and send a test message using Javascript like so it works great:
$.connection.hub.start().done(function () {
chat.server.send("Username", "This is a test message");
});
And my C# send method in the Hub sends the message like so:
public void Send(string username, string message)
{
string name = Context.User.Identity.Name;
Clients.Group(username).getMessages("From: " + name + " - " + message);
}
The problem arises when i try to call the Send method via C#, like this:
ChatHub ch = new ChatHub();
ch.Send("Username", "This is a test message");
When it hits the method during debugging, the Context object is null and it fails.
Essentially, a user sends a message in the View, it hits a controller method, this method calls a notification method in a separate helper class, and this separate class calls the Send method of my Signalr Hub.
Would I need to get the context in the controller, and pass it to the helper class, and then to the Hub? Or is there a better, alternative approach?
Thanks.
UPDATE
I did manage to get the username using:
string name = System.Web.HttpContext.Current.User.Identity.Name;
However, even if I do this, it now throws an exception when it hits this line:
Clients.Group(username).getMessages("From: " + name + " - " + message);
So i think there's a context issue when calling Send from C# only (not from Javascript)

Answer 1

So it turns out from reading this: https://stackoverflow.com/a/36988086/4181058
"If you want to send messages to clients from your own code that runs outside the Hub class, you can't do it by instantiating a Hub class instance, but you can do it by getting a reference to the SignalR context object for your Hub class."
So my solution instead of this:
ChatHub ch = new ChatHub();
ch.Send("Username", "This is a test message");
Was this:
var context = GlobalHost.ConnectionManager.GetHubContext<ChatHub>();
context.Clients.Group(username).getMessages("From: " + name + " - " + message);