void OnConnectionChanged(object sender, ConnectionChangedEventArgs e)
 {
     if (ConnectionChanged != null)
     {
         ConnectionChanged(sender, e);
     }
 }
        void OnConnectionChanged(object sender, ConnectionChangedEventArgs e)
        {
            if (e.IsConnected != connected)
            {
                string message = null;
                if (e.IsConnected)
                {
                    message = "connected";
                }
                else if (connected)
                {
                    message = "lost connection";
                }

                if (!e.IsConnected)
                {
                    Console.WriteLine("Not connected");
                }

                Console.WriteLine(message);
            }
            connected = e.IsConnected;
        }