private void Listen_Callback(IAsyncResult ar)
{
TcpListener s = (TcpListener)ar.AsyncState;
TcpClient s2 = s.EndAcceptTcpClient(ar);
SimpleTcpClient <T> stc = new SimpleTcpClient <T>();
stc.Socket = s2;
stc.Disconnect += disconnect;
stc.ReceivePacket += Switch;
stc.ns = s2.GetStream();
stc.StartRecv();
Clients.Add(stc);
OnClientComing?.Invoke(stc);
s.BeginAcceptTcpClient(new AsyncCallback(Listen_Callback), s);
}