Cómo: Implementar un servicio reconocible que se registra con el proxy de detección

Artículo
02/27/2011

Este tema es el segundo de cuatro temas que describe cómo implementar un proxy de detección. En el tema anterior, Cómo: Implementar un proxy de detección, implementó un proxy de detección. En este tema, creará un servicio de WCF que enviará mensajes de anuncio (Hello y Bye) al proxy de detección, haciendo que se registre y se elimine del registro con el proxy de detección.

Para definir el contrato de servicio

Agregue un nuevo proyecto de aplicación de consola a la solución DiscoveryProxyExample denominada Service.
Agregue referencias a los ensamblados siguientes:
1. System.ServiceModel
2. System.ServiceModel.Discovery
Agregue una nueva clase al proyecto CalculatorService.
Agregue las siguientes instrucciones de uso.
```
using System;
using System.ServiceModel;
```

Dentro de CalculatorService.cs, defina el contrato de servicios.

// 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);
    }

También dentro de CalculatorService.cs, implemente el contrato de servicios.

// 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;
        }
    }

Para hospedar el servicio

Abra el archivo Program.cs que se generó cuando creó el proyecto.

Agregue las siguientes instrucciones de uso.

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

Agregue el código siguiente en el método 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();
}

Ha completado la implementación de un servicio que se puede detectar. Continúe en Cómo: Implementar una aplicación cliente que utiliza el proxy de detección para buscar un servicio.

Ejemplo

Esta es la lista completa del código empleado en este tema.

    // 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();
                }
            }
        }
    }

Vea también

Tareas

Cómo: Implementar un proxy de detección
Cómo: Implementar una aplicación cliente que utiliza el proxy de detección para buscar un servicio

Otros recursos

Detección de WCF

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