获取 WCF 回调以与 netTcpBinding 配合使用

Question

我在使用我的netTcpBinding WCF客户端/服务器进行回调时遇到一些问题。 这是代码...有什么想法吗？

服务端

合同：

using System.Runtime.Serialization;
using System.ServiceModel;
namespace API.Interface
{
   [ServiceContract(CallbackContract = typeof(IServiceCallback))]
   public interface IMyService
   {
       [OperationContract]
       void DoSomething();
   }
   public interface IServiceCallback
   {
        [OperationContract(IsOneWay = true)]
        void OnCallback();
   }
}

服务：

using System;
using System.Security.Cryptography.X509Certificates;
using System.ServiceModel;
using System.Timers;
using API.Interface;
namespace API.Service
{
    [ServiceBehavior(InstanceContextMode = InstanceContextMode.Single, ConcurrencyMode = ConcurrencyMode.Reentrant)]
    public class MyService : IMyService
    {
        public static IServiceCallback callback;
        public static Timer Timer;
        public void DoSomething()
        {
            Console.WriteLine("> Session opened at {0}", DateTime.Now);
            callback = OperationContext.Current.GetCallbackChannel<IServiceCallback>();
            Timer = new Timer(1000);
            Timer.Elapsed += OnTimerElapsed;
            Timer.Enabled = true;
        }
        void OnTimerElapsed(object sender, ElapsedEventArgs e)
        {
            callback.OnCallback();
        }
    }
}

这是我用来启动服务的代码

        var service = new MyService();
        // Start up the WCF API
        var service = new ServiceHost(turboService);
        service.Open();

这是应用程序配置

。

   <system.serviceModel>
    <services>
      <service name="API.Service.MyService">
        <endpoint address="" binding="netTcpBinding" bindingConfiguration=""
          contract="API.Interface.IMyService">
          <identity>
            <dns value="localhost" />
          </identity>
        </endpoint>
        <endpoint address="mex" binding="mexTcpBinding" bindingConfiguration=""
          contract="IMetadataExchange" />
        <host>
          <baseAddresses>
            <add baseAddress="net.tcp://localhost:8732/MyService/"/>
          </baseAddresses>
        </host>
      </service>
    </services>
    <behaviors>
      <serviceBehaviors>
        <behavior name="">
          <serviceMetadata httpGetEnabled="false" />
          <serviceDebug includeExceptionDetailInFaults="false" />
        </behavior>
      </serviceBehaviors>
    </behaviors>
  </system.serviceModel>

客户端

回调服务

using System;
using System.Collections.Generic;
using System.Linq;
using System.ServiceModel;
using System.Text;
using USBAutomationTester.ServiceReference;
namespace USBAutomationTester
{
    [CallbackBehavior(ConcurrencyMode = ConcurrencyMode.Reentrant, UseSynchronizationContext = false)]
    public class CallbackService : IMyServiceCallback
    {
        public void OnCallback()
        {
            Console.WriteLine("> Received callback at {0}", DateTime.Now);
        }
    }
}

连接和呼叫

 var instanceContext = new InstanceContext(new CallbackService());
 var service = new TurboValidateServiceClient(instanceContext);
 service.DoSomething();

应用配置

版

  <system.serviceModel>
    <bindings>
      <netTcpBinding>
        <binding name="NetTcpBinding_IMyService" />
      </netTcpBinding>
    </bindings>
    <client>
      <endpoint address="net.tcp://localhost:8732/MyService/"
        binding="netTcpBinding" bindingConfiguration="NetTcpBinding_ITurboValidateService"
        contract="ServiceReference.IMyService"
        name="NetTcpBinding_IMyService">
        <identity>
          <dns value="localhost" />
        </identity>
      </endpoint>
    </client>
  </system.serviceModel>

我相信我有所有需要的东西。 谷歌搜索引导我走上了几条不同的道路，但没有真正的结果。 我可以看到服务调用回调，但我的客户端从未收到它。

提前感谢，我知道这是一个 WCF 101 类型的问题，但在这一点上我很困惑。

更新

在客户端上，我收到此异常

"无法处理带有操作的传入消息，因为它以请求-答复操作为目标，但由于未设置 MessageId 属性，因此无法答复。"

其次

"通道在关闭时收到带有操作'http://tempuri.org/IMyService/OnCallback'的意外输入消息。只有当你不期待更多的输入消息时，你才应该关闭你的频道。

Answer 1

问题可能是在计时器触发时上下文已经关闭。

    public void DoSomething()
    {
        Console.WriteLine("> Session opened at {0}", DateTime.Now);
        callback = OperationContext.Current.GetCallbackChannel<IServiceCallback>();
        Timer = new Timer(1000);
        Timer.Elapsed += OnTimerElapsed;
        Timer.Enabled = true;
    }
    void OnTimerElapsed(object sender, ElapsedEventArgs e)
    {
        callback.OnCallback();
    }

尝试将回调强制转换为ICommunicationObject并检查State属性。如果在尝试OnCallback时未设置为Open，那就是您的问题。