Object reference is required for non-static "notificationhub" field, method or property

Question

Follows code:

void OnChange(object sender, SqlNotificationEventArgs e)
{
    //from here we will send notification message to client
    NotificationHub.SendNotification("João"); // <----- Aqui

    ....
}

Hub:

public void SendNotification(string who)
{
    string name = HttpContext.Current.User.Identity.Name;

    foreach (var connectionId in _connections.GetConnections(who))
    {
        Clients.Client(connectionId).addNotification(name + ": " + "message");
    }
}

Line error NotificationHub.SendNotification(Who); :

An object reference is required for the field, method or non-static "Notificationhub.Sendnotification(string)" property

Some solution ?

Answer 1

Yes. Exactly what it says in the error message, it is necessary to create an instance of NotificationHub to call the method SendNotification(). That’s because the method is non-static, that is, it can only be accessed by one instance of the class.

Depending on the case, a specific instance will be required, but I have no way to talk about it because there are no details in the question.

NotificationHub notHub = new NotificationHub();
notHub.SendNotification("João");