Procédure : implémenter une application cliente qui utilise le proxy de détection pour rechercher un service

Article
04/07/2023

Cette rubrique est la troisième d'une série de trois qui expliquent comment implémenter un proxy de découverte. Dans la rubrique précédente, Guide pratique pour implémenter un service détectable qui s’inscrit auprès du proxy de découverte, vous avez implémenté un service WCF qui s’inscrit auprès du proxy de découverte. Dans cette rubrique, vous créez un client WCF qui utilise le proxy de découverte pour rechercher le service WCF.

Implémenter le client

Ajoutez à la solution DiscoveryProxyExample un nouveau projet d'application console nommé Client.
Ajoutez des références aux assemblys suivants :
1. System.ServiceModel
2. System.ServiceModel.Discovery
Ajoutez au projet le fichier GeneratedClient.cs qui se trouve en bas de cette rubrique.

Notes

Ce fichier est habituellement généré à l'aide d'un outil tel que Svcutil.exe. Il est fourni dans cette rubrique pour simplifier la tâche.

Ouvrez le fichier Program.cs et ajoutez la méthode suivante. Cette méthode prend une adresse de point de terminaison et l'utilise pour initialiser le client du service (proxy).

static void InvokeCalculatorService(EndpointAddress endpointAddress)
{
    // Create a client
    CalculatorServiceClient client = new CalculatorServiceClient(new NetTcpBinding(), endpointAddress);
    Console.WriteLine("Invoking CalculatorService at {0}", endpointAddress.Uri);
    Console.WriteLine();

    double value1 = 100.00D;
    double value2 = 15.99D;

    // Call the Add service operation.
    double result = client.Add(value1, value2);
    Console.WriteLine("Add({0},{1}) = {2}", value1, value2, result);

    // Call the Subtract service operation.
    result = client.Subtract(value1, value2);
    Console.WriteLine("Subtract({0},{1}) = {2}", value1, value2, result);

    // Call the Multiply service operation.
    result = client.Multiply(value1, value2);
    Console.WriteLine("Multiply({0},{1}) = {2}", value1, value2, result);

    // Call the Divide service operation.
    result = client.Divide(value1, value2);
    Console.WriteLine("Divide({0},{1}) = {2}", value1, value2, result);
    Console.WriteLine();

    // Closing the client gracefully closes the connection and cleans up resources
    client.Close();
}

Ajoutez le code suivant à la méthode Main .

public static void Main()
{
    // Create a DiscoveryEndpoint that points to the DiscoveryProxy
    Uri probeEndpointAddress = new Uri("net.tcp://localhost:8001/Probe");
    DiscoveryEndpoint discoveryEndpoint = new DiscoveryEndpoint(new NetTcpBinding(), new EndpointAddress(probeEndpointAddress));

    // Create a DiscoveryClient passing in the discovery endpoint
    DiscoveryClient discoveryClient = new DiscoveryClient(discoveryEndpoint);

    Console.WriteLine("Finding ICalculatorService endpoints using the proxy at {0}", probeEndpointAddress);
    Console.WriteLine();

    try
    {
        // Search for services that implement ICalculatorService
        FindResponse findResponse = discoveryClient.Find(new FindCriteria(typeof(ICalculatorService)));

        Console.WriteLine("Found {0} ICalculatorService endpoint(s).", findResponse.Endpoints.Count);
        Console.WriteLine();

        // Check to see if endpoints were found, if so then invoke the service.
        if (findResponse.Endpoints.Count > 0)
        {
            InvokeCalculatorService(findResponse.Endpoints[0].Address);
        }
    }
    catch (TargetInvocationException)
    {
        Console.WriteLine("This client was unable to connect to and query the proxy. Ensure that the proxy is up and running.");
    }

    Console.WriteLine("Press <ENTER> to exit.");
    Console.ReadLine();
}

Vous avez terminé l'implémentation de l'application cliente. Passez au Guide pratique pour tester le proxy de découverte.

Exemple

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

// GeneratedClient.cs
//----------------------------------------------------------------
// Copyright (c) Microsoft Corporation.  All rights reserved.
//----------------------------------------------------------------
//------------------------------------------------------------------------------
// <auto-generated>
//     This code was generated by a tool.
//     Runtime Version:2.0.50727.1434
//
//     Changes to this file may cause incorrect behavior and will be lost if
//     the code is regenerated.
// </auto-generated>
//------------------------------------------------------------------------------

namespace Microsoft.Samples.Discovery
{
    [System.CodeDom.Compiler.GeneratedCodeAttribute("System.ServiceModel", "4.0.0.0")]
    [System.ServiceModel.ServiceContractAttribute(Namespace = "http://Microsoft.Samples.Discovery", ConfigurationName = "ICalculatorService")]
    public interface ICalculatorService
    {

        [System.ServiceModel.OperationContractAttribute(ProtectionLevel = System.Net.Security.ProtectionLevel.EncryptAndSign, Action = "http://Microsoft.Samples.Discovery/ICalculatorService/Add", ReplyAction = "http://Microsoft.Samples.Discovery/ICalculatorService/AddResponse")]
        double Add(double n1, double n2);

        [System.ServiceModel.OperationContractAttribute(ProtectionLevel = System.Net.Security.ProtectionLevel.EncryptAndSign, Action = "http://Microsoft.Samples.Discovery/ICalculatorService/Subtract", ReplyAction = "http://Microsoft.Samples.Discovery/ICalculatorService/SubtractResponse")]
        double Subtract(double n1, double n2);

        [System.ServiceModel.OperationContractAttribute(ProtectionLevel = System.Net.Security.ProtectionLevel.EncryptAndSign, Action = "http://Microsoft.Samples.Discovery/ICalculatorService/Multiply", ReplyAction = "http://Microsoft.Samples.Discovery/ICalculatorService/MultiplyResponse")]
        double Multiply(double n1, double n2);

        [System.ServiceModel.OperationContractAttribute(ProtectionLevel = System.Net.Security.ProtectionLevel.EncryptAndSign, Action = "http://Microsoft.Samples.Discovery/ICalculatorService/Divide", ReplyAction = "http://Microsoft.Samples.Discovery/ICalculatorService/DivideResponse")]
        double Divide(double n1, double n2);
    }

    [System.CodeDom.Compiler.GeneratedCodeAttribute("System.ServiceModel", "4.0.0.0")]
    public interface ICalculatorServiceChannel : ICalculatorService, System.ServiceModel.IClientChannel
    {
    }

    [System.Diagnostics.DebuggerStepThroughAttribute()]
    [System.CodeDom.Compiler.GeneratedCodeAttribute("System.ServiceModel", "4.0.0.0")]
    public partial class CalculatorServiceClient : System.ServiceModel.ClientBase<ICalculatorService>, ICalculatorService
    {

        public CalculatorServiceClient()
        {
        }

        public CalculatorServiceClient(string endpointConfigurationName) :
            base(endpointConfigurationName)
        {
        }

        public CalculatorServiceClient(string endpointConfigurationName, string remoteAddress) :
            base(endpointConfigurationName, remoteAddress)
        {
        }

        public CalculatorServiceClient(string endpointConfigurationName, System.ServiceModel.EndpointAddress remoteAddress) :
            base(endpointConfigurationName, remoteAddress)
        {
        }

        public CalculatorServiceClient(System.ServiceModel.Channels.Binding binding, System.ServiceModel.EndpointAddress remoteAddress) :
            base(binding, remoteAddress)
        {
        }

        public double Add(double n1, double n2)
        {
            return base.Channel.Add(n1, n2);
        }

        public double Subtract(double n1, double n2)
        {
            return base.Channel.Subtract(n1, n2);
        }

        public double Multiply(double n1, double n2)
        {
            return base.Channel.Multiply(n1, n2);
        }

        public double Divide(double n1, double n2)
        {
            return base.Channel.Divide(n1, n2);
        }
    }
}

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

using System;
using System.Reflection;
using System.ServiceModel;
using System.ServiceModel.Discovery;

namespace Microsoft.Samples.Discovery
{
    class Client
    {
        public static void Main()
        {
            // Create a DiscoveryEndpoint that points to the DiscoveryProxy
            Uri probeEndpointAddress = new Uri("net.tcp://localhost:8001/Probe");
            DiscoveryEndpoint discoveryEndpoint = new DiscoveryEndpoint(new NetTcpBinding(), new EndpointAddress(probeEndpointAddress));

            DiscoveryClient discoveryClient = new DiscoveryClient(discoveryEndpoint);

            Console.WriteLine("Finding ICalculatorService endpoints using the proxy at {0}", probeEndpointAddress);
            Console.WriteLine();

            try
            {
                // Find ICalculatorService endpoints
                FindResponse findResponse = discoveryClient.Find(new FindCriteria(typeof(ICalculatorService)));

                Console.WriteLine("Found {0} ICalculatorService endpoint(s).", findResponse.Endpoints.Count);
                Console.WriteLine();

                // Check to see if endpoints were found, if so then invoke the service.
                if (findResponse.Endpoints.Count > 0)
                {
                    InvokeCalculatorService(findResponse.Endpoints[0].Address);
                }
            }
            catch (TargetInvocationException)
            {
                Console.WriteLine("This client was unable to connect to and query the proxy. Ensure that the proxy is up and running.");
            }

            Console.WriteLine("Press <ENTER> to exit.");
            Console.ReadLine();
        }

        static void InvokeCalculatorService(EndpointAddress endpointAddress)
        {
            // Create a client
            CalculatorServiceClient client = new CalculatorServiceClient(new NetTcpBinding(), endpointAddress);
            Console.WriteLine("Invoking CalculatorService at {0}", endpointAddress.Uri);
            Console.WriteLine();

            double value1 = 100.00D;
            double value2 = 15.99D;

            // Call the Add service operation.
            double result = client.Add(value1, value2);
            Console.WriteLine("Add({0},{1}) = {2}", value1, value2, result);

            // Call the Subtract service operation.
            result = client.Subtract(value1, value2);
            Console.WriteLine("Subtract({0},{1}) = {2}", value1, value2, result);

            // Call the Multiply service operation.
            result = client.Multiply(value1, value2);
            Console.WriteLine("Multiply({0},{1}) = {2}", value1, value2, result);

            // Call the Divide service operation.
            result = client.Divide(value1, value2);
            Console.WriteLine("Divide({0},{1}) = {2}", value1, value2, result);
            Console.WriteLine();

            // Closing the client gracefully closes the connection and cleans up resources
            client.Close();
        }
    }
}

Procédure : implémenter une application cliente qui utilise le proxy de détection pour rechercher un service

Implémenter le client

Exemple

Voir aussi

Ressources supplémentaires