Procédure : implémenter un service détectable qui s’enregistre auprès du proxy de détection

Article
06/13/2024

Cette rubrique est la deuxième d'une série de quatre rubriques qui expliquent comment implémenter un proxy de découverte. Dans la rubrique précédente, Guide pratique pour implémenter un proxy de découverte, vous avez implémenté un proxy de découverte. Dans cette rubrique, vous créez un service WCF qui envoie au proxy de découverte des messages d’annonce (Hello et Bye) qui permettent au service de s’inscrire et de se désinscrire du proxy de découverte.

Pour définir le contrat de service

Ajoutez à la solution DiscoveryProxyExample un nouveau projet d'application console nommé Service.
Ajoutez des références aux assemblys suivants :
1. System.ServiceModel
2. System.ServiceModel.Discovery
Ajoutez une nouvelle classe au projet nommé CalculatorService.

Ajoutez les directives using suivantes.

using System;
using System.ServiceModel;

Dans CalculatorService.cs, définissez le contrat de service.

// Define a service contract.
[ServiceContract(Namespace = "http://Microsoft.Samples.Discovery")]
public interface ICalculatorService
{
    [OperationContract]
    double Add(double n1, double n2);
    [OperationContract]
    double Subtract(double n1, double n2);
    [OperationContract]
    double Multiply(double n1, double n2);
    [OperationContract]
    double Divide(double n1, double n2);
}

Également dans CalculatorService.cs, implémentez le contrat de service.

// Service class which implements the service contract.
public class CalculatorService : ICalculatorService
{
    public double Add(double n1, double n2)
    {
        double result = n1 + n2;
        Console.WriteLine("Received Add({0},{1})", n1, n2);
        Console.WriteLine("Return: {0}", result);
        return result;
    }

    public double Subtract(double n1, double n2)
    {
        double result = n1 - n2;
        Console.WriteLine("Received Subtract({0},{1})", n1, n2);
        Console.WriteLine("Return: {0}", result);
        return result;
    }

    public double Multiply(double n1, double n2)
    {
        double result = n1 * n2;
        Console.WriteLine("Received Multiply({0},{1})", n1, n2);
        Console.WriteLine("Return: {0}", result);
        return result;
    }

    public double Divide(double n1, double n2)
    {
        double result = n1 / n2;
        Console.WriteLine("Received Divide({0},{1})", n1, n2);
        Console.WriteLine("Return: {0}", result);
        return result;
    }
}

Pour héberger le service

Ouvrez le fichier Program.cs qui a été généré lorsque vous avez créé le projet.

Ajoutez les directives using suivantes.

using System;
using System.ServiceModel;
using System.ServiceModel.Description;
using System.ServiceModel.Discovery;

Ajoutez le code suivant dans la méthode Main() :

// Define the base address of the service
Uri baseAddress = new Uri("net.tcp://localhost:9002/CalculatorService/" + Guid.NewGuid().ToString());
// Define the endpoint address where announcement messages will be sent
Uri announcementEndpointAddress = new Uri("net.tcp://localhost:9021/Announcement");

// Create the service host
ServiceHost serviceHost = new ServiceHost(typeof(CalculatorService), baseAddress);
try
{
    // Add a service endpoint
    ServiceEndpoint netTcpEndpoint = serviceHost.AddServiceEndpoint(typeof(ICalculatorService),
        new NetTcpBinding(), string.Empty);

    // Create an announcement endpoint, which points to the Announcement Endpoint hosted by the proxy service.
    AnnouncementEndpoint announcementEndpoint = new AnnouncementEndpoint(new NetTcpBinding(),
        new EndpointAddress(announcementEndpointAddress));

    // Create a ServiceDiscoveryBehavior and add the announcement endpoint
    ServiceDiscoveryBehavior serviceDiscoveryBehavior = new ServiceDiscoveryBehavior();
    serviceDiscoveryBehavior.AnnouncementEndpoints.Add(announcementEndpoint);

    // Add the ServiceDiscoveryBehavior to the service host to make the service discoverable
    serviceHost.Description.Behaviors.Add(serviceDiscoveryBehavior);

    // Start listening for messages
    serviceHost.Open();

    Console.WriteLine("Calculator Service started at {0}", baseAddress);
    Console.WriteLine();
    Console.WriteLine("Press <ENTER> to terminate the service.");
    Console.WriteLine();
    Console.ReadLine();

    serviceHost.Close();
}
catch (CommunicationException e)
{
    Console.WriteLine(e.Message);
}
catch (TimeoutException e)
{
    Console.WriteLine(e.Message);
}

if (serviceHost.State != CommunicationState.Closed)
{
    Console.WriteLine("Aborting the service...");
    serviceHost.Abort();
}

Vous avez terminé l'implémentation d'un service détectable. Poursuivez avec Guide pratique pour implémenter une application cliente qui utilise le proxy de découverte pour rechercher un service.

Exemple

Les éléments suivants représentent l'intégralité du code utilisé dans cette rubrique.

// CalculatorService.cs
//----------------------------------------------------------------
// Copyright (c) Microsoft Corporation.  All rights reserved.
//----------------------------------------------------------------

using System;
using System.ServiceModel;

namespace Microsoft.Samples.Discovery
{
    // Define a service contract.
    [ServiceContract(Namespace = "http://Microsoft.Samples.Discovery")]
    public interface ICalculatorService
    {
        [OperationContract]
        double Add(double n1, double n2);
        [OperationContract]
        double Subtract(double n1, double n2);
        [OperationContract]
        double Multiply(double n1, double n2);
        [OperationContract]
        double Divide(double n1, double n2);
    }

    // Service class which implements the service contract.
    public class CalculatorService : ICalculatorService
    {
        public double Add(double n1, double n2)
        {
            double result = n1 + n2;
            Console.WriteLine("Received Add({0},{1})", n1, n2);
            Console.WriteLine("Return: {0}", result);
            return result;
        }

        public double Subtract(double n1, double n2)
        {
            double result = n1 - n2;
            Console.WriteLine("Received Subtract({0},{1})", n1, n2);
            Console.WriteLine("Return: {0}", result);
            return result;
        }

        public double Multiply(double n1, double n2)
        {
            double result = n1 * n2;
            Console.WriteLine("Received Multiply({0},{1})", n1, n2);
            Console.WriteLine("Return: {0}", result);
            return result;
        }

        public double Divide(double n1, double n2)
        {
            double result = n1 / n2;
            Console.WriteLine("Received Divide({0},{1})", n1, n2);
            Console.WriteLine("Return: {0}", result);
            return result;
        }
    }
}

// Program.cs
//----------------------------------------------------------------
// Copyright (c) Microsoft Corporation.  All rights reserved.
//----------------------------------------------------------------

using System;
using System.ServiceModel;
using System.ServiceModel.Description;
using System.ServiceModel.Discovery;

namespace Microsoft.Samples.Discovery
{
    class Program
    {
        public static void Main()
        {
            Uri baseAddress = new Uri("net.tcp://localhost:9002/CalculatorService/" + Guid.NewGuid().ToString());
            Uri announcementEndpointAddress = new Uri("net.tcp://localhost:9021/Announcement");

            ServiceHost serviceHost = new ServiceHost(typeof(CalculatorService), baseAddress);
            try
            {
                ServiceEndpoint netTcpEndpoint = serviceHost.AddServiceEndpoint(typeof(ICalculatorService),
                    new NetTcpBinding(), string.Empty);

                // Create an announcement endpoint, which points to the Announcement Endpoint hosted by the proxy service.
                AnnouncementEndpoint announcementEndpoint = new AnnouncementEndpoint(new NetTcpBinding(),
                    new EndpointAddress(announcementEndpointAddress));

                ServiceDiscoveryBehavior serviceDiscoveryBehavior = new ServiceDiscoveryBehavior();
                serviceDiscoveryBehavior.AnnouncementEndpoints.Add(announcementEndpoint);

                // Make the service discoverable
                serviceHost.Description.Behaviors.Add(serviceDiscoveryBehavior);

                serviceHost.Open();

                Console.WriteLine("Calculator Service started at {0}", baseAddress);
                Console.WriteLine();
                Console.WriteLine("Press <ENTER> to terminate the service.");
                Console.WriteLine();
                Console.ReadLine();

                serviceHost.Close();
            }
            catch (CommunicationException e)
            {
                Console.WriteLine(e.Message);
            }
            catch (TimeoutException e)
            {
                Console.WriteLine(e.Message);
            }

            if (serviceHost.State != CommunicationState.Closed)
            {
                Console.WriteLine("Aborting the service...");
                serviceHost.Abort();
            }
        }
    }
}

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Procédure : implémenter un service détectable qui s’enregistre auprès du proxy de détection

Pour définir le contrat de service

Pour héberger le service

Exemple

Voir aussi

Ressources supplémentaires