Question

我有一个带回叫接口的简单WCF应用程序。我想要的是在客户端的回调函数中调用其他WCF服务。

但是当我尝试做的时候，我得到了异常

DetailsSystem.ServiceModel.CommunicationException：服务器没有提供有意义的答复;这可能是合同造成的不匹配，过早的会话关闭或内部服务器错误。

这是合同：

   [ServiceContract(CallbackContract = typeof(IMyServiceCallback))]
    public interface IMyService
    {
        [OperationContract]
        void DoAddition(int numberOne, int numberTwo);

        [OperationContract]
        double Pow(double number, double power);
    }

    public interface IMyServiceCallback
   {
    [OperationContract]
    void OnCallback(string result);
   }

这是简单的服务实现

[ServiceBehavior(ConcurrencyMode = ConcurrencyMode.Multiple)]
    public class MyCustomService : IMyService
    {
        public void DoAddition(int numberOne, int numberTwo)
        {
            Console.WriteLine("Now Do Addition called");

            var callback = OperationContext.Current.
            GetCallbackChannel<IMyServiceCallback>();

            callback.OnCallback("The result is="  + numberOne + numberTwo );
        }

        public double Pow(double number, double power)
        {
            double result = 0;
            try
            {
                Console.WriteLine("Now Pow called");
                result= Math.Pow(number, power);
            }
            catch (Exception e)
            {
               Console.WriteLine("Error:" + e);
            }

            return result;

        }
    }

我将此作为服务托管在

中

callServiceHost = new ServiceHost(typeof(MyService.MyCustomService));
callServiceHost.AddServiceEndpoint(typeof (IMyService), new WSDualHttpBinding(), new Uri(GetUri()));
callServiceHost.Open();
Console.WriteLine("Press  to terminate.\n\n");
Console.ReadLine();

在客户端，我想在回调函数中调用wcf服务，以便

[ServiceContract(CallbackContract = typeof(IMyServiceCallback))]
public class MyServiceCallback : IMyServiceCallback
    {
        public void OnCallback(string result)
        {
            Console.WriteLine("From Server I got the result" + result);
            Console.WriteLine(result);

            double powValue = Service.Pow(2, 3);

            Console.WriteLine("Power=" + powValue);
        }

        public IMyService Service { get; set; }
    }

我的客户代码

var binding = new WSDualHttpBinding();
var address = new EndpointAddress(GetUri());

var callback = new MyServiceCallback();
var instanceContext = new InstanceContext(callback);

var factory = new DuplexChannelFactory<IMyService>(instanceContext, binding, address);
IMyService callService = factory.CreateChannel();
callback.Service = callService;

callService.DoAddition(4,6);

Console.ReadKey();

Answer 1

我认为您的IMyServiceCallback接口缺少[ServiceContract]装饰。您是否也可以更改您的运营合同[OperationContract(IsOneWay = true)]

在客户端的回调函数内调用其他WCF服务

1 个答案: