在客戶端的回調函數中調用其他WCF服務

Question

我有一個帶有回調接口的簡單WCF應用程序。 我想要的是在客戶端的回調函數內調用其他WCF服務。

但是當我嘗試做的時候，我得到了例外

DetailsS​​ystem.ServiceModel.CommunicationException：服務器未提供有意義的答復。 這可能是由於合同不匹配，會話過早關閉或內部服務器錯誤引起的。

這是合同：

   [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);
   }

這是簡單的服務實現

[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;

        }
    }

我將其作為服務托管在控制台中

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();

在客戶端，我想在回調函數中調用wcf服務，這樣

[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; }
    }

我的客戶代碼是

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

我認為您的IMyServiceCallback接口缺少[ServiceContract]裝飾。 您還可以更改運營合同[OperationContract(IsOneWay = true)]