问ActionScript 3 XMLSocket的策略文件出现问题

EN

<?xml version="1.0" encoding="UTF-8"?>
<cross-domain-policy>
  <site-control permitted-cross-domain-policies="master-only"/>
  <allow-access-from domain="*" to-ports="*" secure="false"/>
</cross-domain-policy>

Server.LogMessage("Policy Server: Serving policy file.");
            TcpListener listener = (TcpListener)ar.AsyncState;
            Socket client = listener.EndAcceptSocket(ar);
            NetworkStream ns = new NetworkStream(client);
            StreamReader sr = new StreamReader(ns);
            StreamWriter sw = new StreamWriter(ns);

            sr.Read();
            //Send policy
            sw.Write(Server.EncodeString(Server.xmlPolicyFile.OuterXml) + "\0");
            sw.Flush();
            ns.Flush();
            //Cleanup
            sw.Close();
            sr.Close();
            ns.Close();
            //Do it again!
            tcl.BeginAcceptSocket(AcceptCallback, tcl);