如何配置WCF以使用Azure ACS的URN格式的自定义Realm？

      EndpointAddress serviceEndpointAddress = new EndpointAddress( new Uri( "http://localhost:7000/Service/Default.aspx"),  
                                                                      EndpointIdentity.CreateDnsIdentity( GetServiceCertificateSubjectName() ),
                                                                      new AddressHeaderCollection() );

        ChannelFactory<IStringService> stringServiceFactory = new ChannelFactory<IStringService>(Bindings.CreateServiceBinding("https://agent7.accesscontrol.appfabriclabs.com/v2/wstrust/13/certificate"), serviceEndpointAddress );

        // Set the service credentials.
        stringServiceFactory.Credentials.ServiceCertificate.Authentication.CertificateValidationMode = X509CertificateValidationMode.None;
        stringServiceFactory.Credentials.ServiceCertificate.DefaultCertificate = GetServiceCertificate();

        // Set the client credentials.
        stringServiceFactory.Credentials.ClientCertificate.Certificate = GetClientCertificateWithPrivateKey();

 string acsCertificateEndpoint = String.Format( "https://{0}.{1}/v2/wstrust/13/certificate", AccessControlNamespace, AccessControlHostName );

        ServiceHost rpHost = new ServiceHost( typeof( StringService ) );

        rpHost.Credentials.ServiceCertificate.Certificate = GetServiceCertificateWithPrivateKey();

        rpHost.AddServiceEndpoint( typeof( IStringService ),
                                   Bindings.CreateServiceBinding( acsCertificateEndpoint ),
                                   "http://localhost:7000/Service/Default.aspx"
                                   );

        //
        // This must be called after all WCF settings are set on the service host so the
        // Windows Identity Foundation token handlers can pick up the relevant settings.
        //
        ServiceConfiguration serviceConfiguration = new ServiceConfiguration();
        serviceConfiguration.CertificateValidationMode = X509CertificateValidationMode.None;

        // Accept ACS signing certificate as Issuer.
        serviceConfiguration.IssuerNameRegistry = new X509IssuerNameRegistry( GetAcsSigningCertificate().SubjectName.Name );

        // Add the SAML 2.0 token handler.
        serviceConfiguration.SecurityTokenHandlers.AddOrReplace( new Saml2SecurityTokenHandler() );

        // Add the address of this service to the allowed audiences.
        serviceConfiguration.SecurityTokenHandlers.Configuration.AudienceRestriction.AllowedAudienceUris.Add( new Uri( "urn:federation:customer:222:agent:11") );

        FederatedServiceCredentials.ConfigureServiceHost( rpHost, serviceConfiguration );

        return rpHost;

urn:federation:customer:222:agent:11

http://localhost:7000/Service/Default.aspx

AudienceRestriction