WCF：通知双方的客户端服务器连接（服务自托管作为控制台应用程序）

Question

我有一个 WCF 服务，它自托管在控制台应用程序上。我可以成功连接和通信。

建立连接后，我需要将一些数据从服务器推送到客户端。我怎么能理解客户端已连接，反之亦然（客户端知道服务器连接何时建立）。

//创建一个URI作为基地址 uri httpUrl = new Uri("http://localhost:8090/TAOInventoryService/InventoryManager");

        //Create ServiceHost
        ServiceHost host = new ServiceHost(typeof(TAOInventoryService.InventoryManager), httpUrl);

        //Add a service endpoint
        host.AddServiceEndpoint(typeof(TAOInventoryService.IInventoryManager ), new WSHttpBinding(), "");

        //Enable metadata exchange
        ServiceMetadataBehavior smb = new ServiceMetadataBehavior();
        smb.HttpGetEnabled = true;
        host.Description.Behaviors.Add(smb);

        //Start the Service
        host.Open();
        Console.WriteLine("Service is host at " + DateTime.Now.ToString());
        Console.WriteLine("Host is running... Press  key to stop");
        Console.ReadLine();

Answer 1

我可能不完全理解您的问题。在我看来。这有点像在线和离线通知。服务端在线时，可以主动向客户端推送公告消息。
这是我写过的一个例子，希望对你有用。
Server.

static void Main(string[] args)
        {
            Uri uri = new Uri("http://localhost:21011");
            BasicHttpBinding binding = new BasicHttpBinding();
            binding.Security.Mode = BasicHttpSecurityMode.None;
            using (ServiceHost sh = new ServiceHost(typeof(MyService), uri))
            {
                sh.AddServiceEndpoint(typeof(IService), binding, "");
                ServiceMetadataBehavior smb;
                smb = sh.Description.Behaviors.Find<ServiceMetadataBehavior>();
                if (smb == null)
                {
                    smb = new ServiceMetadataBehavior()
                    {
                        HttpGetEnabled = true
                    };
                    sh.Description.Behaviors.Add(smb);
                }
                ServiceDiscoveryBehavior sdb = new ServiceDiscoveryBehavior();
                sdb.AnnouncementEndpoints.Add(new UdpAnnouncementEndpoint());
                sh.Description.Behaviors.Add(sdb);
                sh.AddServiceEndpoint(new UdpDiscoveryEndpoint());
                Binding mexbinding = MetadataExchangeBindings.CreateMexHttpBinding();
                sh.AddServiceEndpoint(typeof(IMetadataExchange), mexbinding, "mex");
                sh.Opened += delegate
                {
                    Console.WriteLine("Service is ready");                    
                };
                sh.Closed += delegate
                {
                    Console.WriteLine("Service is clsoed");                    
                };
                sh.Open();
                Console.ReadLine();
                //pause
                sh.Close();
                Console.ReadLine();
            }
        }
    }
    [ServiceContract]
    public interface IService
    {
        [OperationContract]
        Int32 Add(Int32 Num1, Int32 Num2);

    }
    [ServiceBehavior]
    public class MyService : IService
    {
        public int Add(int Num1, int Num2)
        {
            return Num1 + Num2;
        }
    }

客户。

static void Main(string[] args)
        {

            Console.Title = "Start client first";

            AnnouncementService annsvc = new AnnouncementService();
            annsvc.OnlineAnnouncementReceived += OnlineRec;
            annsvc.OfflineAnnouncementReceived += OfflineRec;
            using (ServiceHost host = new ServiceHost(annsvc))
            {
                host.AddServiceEndpoint(new UdpAnnouncementEndpoint());
                host.Open();
                Console.Read();
            }
        }

        private static void OfflineRec(object sender, AnnouncementEventArgs e)
        {
            Console.WriteLine($"\nService is offline, service address：{e.EndpointDiscoveryMetadata.Address.Uri}");
        }

        private static void OnlineRec(object sender, AnnouncementEventArgs e)
        {
            Console.WriteLine($"\nService is online, service address：{e.EndpointDiscoveryMetadata.Address.Uri}");
        }

结果。

官方文档。
https://docs.microsoft.com/en-us/previous-versions/dotnet/netframework-4.0/dd483353(v=vs.100)
如果有什么可以帮助的，请随时告诉我。