WCF InvalidOperationException: A binding instance has already been associated to listen URI

Question

I'm a beginner of WCF and still learning the essentials.

I encountered a problem when using ServiceContract NameSpace and Name. When I run the code I get an InvalidOperationException, but I don't quite understand it.

A binding instance has already been associated to listen URI 'http://localhost:8080/NamespaceChange01'. If two endpoints want to share the same ListenUri, they must also share the same binding object instance. The two conflicting endpoints were either specified in AddServiceEndpoint() calls, in a config file, or a combination of AddServiceEndpoint() and config.

Does anyone knows how to prevent an InvalidOperationException?

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.ServiceModel;

namespace NamespaceChange01
{

    [ServiceContract(Name = "MyServiceName", Namespace = "http://ServiceNamespace")]
    public interface IBurgerMaster
    {
        [return: MessageParameter(Name = "myOutput")]
        [OperationContract(Name = "OperationName", Action = "OperationAction", ReplyAction = "ReplyActionName")]
        double GetStockPrice(string ticker);
    }

    [ServiceBehavior(Namespace = "http://MyService")]
    public class BurgerMaster : IBurgerMaster
    {

        public double GetStockPrice(string ticker)
        {
            return 100.99;
        }
    }

    class Program
    {
        static void Main(string[] args)
        {
            ServiceHost host = new ServiceHost(typeof(BurgerMaster));
            host.Open();
            Console.ReadLine();
            host.Close();
        }
    }
}

• app.config

    <?xml version="1.0" encoding="utf-8" ?>
    <configuration>
      <system.serviceModel>
        <services>
          <service name="NamespaceChange01.BurgerMaster" behaviorConfiguration="mexServiceBehavior">
            <host>
              <baseAddresses>
                <add baseAddress="http://localhost:8080/NamespaceChange01"/>
              </baseAddresses>
            </host>
            <endpoint name="basic" binding="basicHttpBinding" contract="NamespaceChange01.IBurgerMaster"/>
            <endpoint name="mex" binding="mexHttpBinding" contract="IMetadataExchange"/>
          </service>
        </services>
        <behaviors>
          <serviceBehaviors>
            <behavior name="mexServiceBehavior">
              <serviceMetadata httpGetEnabled="true"/>
            </behavior>
          </serviceBehaviors>
        </behaviors>
      </system.serviceModel>
    </configuration>
  

Thanks.

Answer 1

Two endpoints (basic and mex) couldn't be on the same address. Add some specific address for one of them (or for both ones).

For example:

<endpoint name="mex" address="mex" binding="mexHttpBinding" contract="IMetadataExchange"/>