DuplexChannel

 [ServiceContract(Namespace = "http://xx.com", CallbackContract = typeof(Ipub_c))]
    public interface Ipub_s
    {
        [OperationContract(IsOneWay = true)]
        void toserver(string cs);
    }
    public interface Ipub_c
    {
        [OperationContract(IsOneWay = true)]
        void toclient(string cs);

    }

 [ServiceBehavior(ConcurrencyMode = ConcurrencyMode.Reentrant)]
    public class Bpub : Ipub_s
    {
        public void toserver(string cs)
        {

            Ipub_c callback = OperationContext.Current.GetCallbackChannel<Ipub_c>();
            for (int i = 0; i < 1000; i++)
            {
                System.Threading.Thread.Sleep(1000);
                callback.toclient(cs + " | " + DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss fff") + " | " + cs);
            }
        }
    }

 ServiceHost host = new ServiceHost(typeof(Bpub));
                host.AddServiceEndpoint(typeof(Ipub_s), new NetTcpBinding(), "net.tcp://localhost/dd");
                host.Opened += (s, ek) =>
                {
                    this.Invoke((Action)delegate
                    {
                        button1.Enabled = false;
                        button1.Text = "已启动";
                        Console.WriteLine("HelloService已经启动，按按回车键终止服务！");
                    });
                };
                host.Open();

     InstanceContext instanceContext = new InstanceContext(new Bcpub());
            DuplexChannelFactory<WcfSgS.Ipub_s> channel = new DuplexChannelFactory<Ipub_s>(instanceContext, new NetTcpBinding(), "net.tcp://localhost/dd");
            Ipub_s proxy = channel.CreateChannel();

            proxy.toserver("dddds");