让netTcpBinding与WCF回调正常工作

Question

我在使用netTcpBinding WCF客户端/服务器时遇到了一些回调问题。以下是代码... 有什么想法吗？

服务端：

协定：

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App.Config文件。

   <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：

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);
        }
    }
}

连接和拨打电话

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

App.Config

  <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>

我相信我已经拥有所有所需的部件。通过谷歌搜索，我走了几条不同的路线，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。

提前感谢您的帮助，我知道这是WCF 101级别的问题，但我现在陷入困境。

更新

在客户端，我得到了这个异常：“传入的消息由于针对请求-应答操作而被定位，但由于未设置MessageId属性，因此无法进行回复处理。”

接着是：“当关闭时，通道收到了一个意外的输入消息，其操作为 'http://tempuri.org/IMyService/OnCallback'。只有在您不再期望任何输入消息时，才应关闭通道。”

- AndySousa

Answer 1

也许问题出在定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();
    }

尝试将您的回调转换为ICommunicationObject并检查State属性。如果在尝试执行OnCallback时它未设置为Open，那么这就是您的问题所在。

- SouthShoreAK

---

它似乎已经打开了几次迭代，然后关闭了。 我仍然没有在客户端上收到回调。 - AndySousa

我移动了一些声明并将它们变为静态的... 看起来这样做有用。谢谢 - AndySousa