1 創建兩個項目

Wcf_WsDual_Service Wcf_WsDual_Client

2 Wcf_WsDual_Service 項目中創建 LoginService.cs 的wcf文件

using System.ServiceModel;

namespace Wcf_WsDual_Service
{
    // 註意: 使用“重構”菜單上的“重命名”命令，可以同時更改代碼和配置文件中的接口名“ILogin”。
    //註意此處構造函數裏面的回調
    [ServiceContract(CallbackContract =typeof(ICallBack))]
    public
 
 interface ILoginService
    {
        [OperationContract]
        void Login(string username);
    }
    //註意此處添加了回調接口
    [ServiceContract]
    public interface ICallBack
    {
        [OperationContract]
        void Notify(string msg);
    }
}

using System;
using System.Collections.Generic;
 
using System.ServiceModel;

namespace Wcf_WsDual_Service
{
    // 註意: 使用“重構”菜單上的“重命名”命令，可以同時更改代碼和配置文件中的類名“Login”。
    public class LoginService : ILoginService
    {
        //存儲所有請求了這個服務的客戶端管道
        public static Dictionary<string, ICallBack> channelDic = new Dictionary<string, ICallBack>();
        
 
void ILoginService.Login(string username)
        {
            //獲得請求帶ICallBack的endpoint的channel
            var callback = OperationContext.Current.GetCallbackChannel<ICallBack>();
            channelDic[username] = callback;
            Console.WriteLine($"用戶{username}已經登錄");
        }
        //服務端動作
        public static void OperateAction()
        {
            while (true)
            {
                string msg = Console.ReadLine();
                if (!string.IsNullOrEmpty(msg))
                {
                    //遍歷客戶端管道 向這些管道發送消息
                    foreach (var item in channelDic)
                    {
                        item.Value.Notify(msg);
                    }

                }

            }
        }
    }
}

3 修改服務配置文件

a 將協議改成雙工 b將對應雙工的安全設置成無安全

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
    <startup> 
        <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.6.1" />
    </startup>
    <system.serviceModel>

     <!--雙工默認有安全驗證 這裏取消安全-->
      <bindings>
        <wsDualHttpBinding>
          <binding name="MyDual">
            <security mode="None"></security>
          </binding>
        </wsDualHttpBinding>
      </bindings>
      
        <behaviors>
            <serviceBehaviors>
                <behavior name="">
                    <serviceMetadata httpGetEnabled="true" httpsGetEnabled="true" />
                    <serviceDebug includeExceptionDetailInFaults="false" />
                </behavior>
            </serviceBehaviors>
        </behaviors>
        <services>
            <service name="Wcf_WsDual_Service.LoginService">
                <endpoint address="" binding="wsDualHttpBinding" bindingConfiguration="MyDual"
                    contract="Wcf_WsDual_Service.ILoginService">
                    <identity>
                        <dns value="localhost" />
                    </identity>
                </endpoint>
                <endpoint address="mex" binding="mexHttpBinding" contract="IMetadataExchange" />
                <host>
                    <baseAddresses>
                        <add baseAddress="http://localhost:8988/Design_Time_Addresses/Wcf_WsDual_Service/Login/" />
                    </baseAddresses>
                </host>
            </service>
        </services>
    </system.serviceModel>
</configuration>

4.在服務端main方法中啟動服務，並異步啟動線程用以向客戶端發送消息

using System;
using System.ServiceModel;
using System.Threading.Tasks;

namespace Wcf_WsDual_Service
{
    class Program
    {
        static void Main(string[] args)
        {
            ServiceHost host = new ServiceHost(typeof(LoginService));
            host.Open();
            Console.WriteLine("服務已經啟動");
            Task.Run(() =>
            {
                LoginService.OperateAction();
            });

            System.Threading.Thread.Sleep(int.MaxValue);
        }
       
    }
    
}

5.客戶端引用服務引用

6.客戶端創建一個LoginCallBack類實現服務端定義的iLoginCallBack接口

  public class LoginCallBack : ILoginServiceCallback
    {
        public void Notify(string msg)
        {
            Console.WriteLine(msg);
        }
    }

7.客戶端main方法創建一個服務實例，並想服務發送請求，在服務端這個請求會記錄下這個請求對應的客戶端的信息

 class Program
    {
        static void Main(string[] args)
        {
            var instanceContext = new InstanceContext(new LoginCallBack());
            LoginServiceClient client = new LoginServiceClient(instanceContext);
            client.Login("winner");
            Console.ReadKey();
        }
    }

8.這樣啟動服務之後，再啟動客戶端，客戶端會給服務端發送一個請求，服務端會記錄下客戶端的endpoint等信息創建一個針對客戶端的管道，服務端就可以利用這個管道向服務端發送消息了

5 wcf雙工