Announcing Online Events in WCF Service

Question Arises: What is Announcement Service in WCF?

Endpoints can be announcement as a collection which is available for the client who is consuming the service will be able to listen when comes online/offline Events. Let's get this concept implemented such that we will have a better idea on this

So, let's get it started off now.

The Complete Code of IService1.cs looks like this:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.Serialization;
using System.ServiceModel;
using System.ServiceModel.Web;
using System.Text;
namespace WcfService2
{
// NOTE: You can use the "Rename" command on the "Refactor" menu to change the interface name "IService1" in both code and config file together.
[ServiceContract]
public interface IService1
{
[OperationContract]
string Hello(string val);
[OperationContract]
string Bye(string val);
}
}

The Complete Code of Service1.svc.cs looks like this:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.Serialization;
using System.ServiceModel;
using System.ServiceModel.Web;
using System.Text;

namespace WcfService2
{
// NOTE: You can use the "Rename" command on the "Refactor" menu to change the class name "Service1" in code, svc and config file together.
public class Service1 : IService1
{

public string Hello(string val)
{
return val;
}

public string Bye(string val)
{
return val;
}
}
}

The Complete Code of Web.Config looks like this:

<?xml version="1.0"?>
<configuration>

<system.web>
<compilation debug="true" targetFramework="4.0" />
</system.web>
<system.serviceModel>
<behaviors>
<serviceBehaviors>
<behavior name="Application">
<serviceDiscovery>
<announcementEndpoints>
<endpoint kind="udpAnnouncementEndpoint"></endpoint>
</announcementEndpoints>
</serviceDiscovery>
<!-- To avoid disclosing metadata information, set the value below to false and remove the metadata endpoint above before deployment -->
<serviceMetadata httpGetEnabled="true"/>
<!-- To receive exception details in faults for debugging purposes, set the value below to true. Set to false before deployment to avoid disclosing exception information -->
<serviceDebug includeExceptionDetailInFaults="false"/>
</behavior>
</serviceBehaviors>
</behaviors>
<serviceHostingEnvironment multipleSiteBindingsEnabled="true" />
<services>
<service name="WcfService2.Service1" behaviorConfiguration="Application">
<endpoint address="/Simple" binding="basicHttpBinding" contract="WcfService2.IService1"></endpoint>
<endpoint kind="udpDiscoveryEndpoint"></endpoint>
<host>
<baseAddresses>
<add baseAddress="http://localhost:52429/Service1.svc"/>
</baseAddresses>
</host>
</service>
</services>

</system.serviceModel>
<system.webServer>
<modules runAllManagedModulesForAllRequests="true"/>
</system.webServer>

</configuration>

The Complete Code of Program.cs looks like this

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using ConsoleApplication1.ServiceReference1;
using System.ServiceModel.Discovery;
using System.ServiceModel;

namespace ConsoleApplication1
{
class Program
{
static void Main(string[] args)
{
// Create an AnnouncementService instance
AnnouncementService announcementService = new AnnouncementService();

// Subscribe the announcement events
announcementService.OnlineAnnouncementReceived += OnOnlineEvent;
announcementService.OfflineAnnouncementReceived += OnOfflineEvent;

// Create ServiceHost for the AnnouncementService
using (ServiceHost announcementServiceHost = new ServiceHost(announcementService))
{
// Listen for the announcements sent over UDP multicast
announcementServiceHost.AddServiceEndpoint(new UdpAnnouncementEndpoint());
announcementServiceHost.Open();
Service1Client obj = new Service1Client();

Console.WriteLine("The Online is " + obj.Hello("Vijay prativadi"));
Console.WriteLine("The Offline is " + obj.Bye("Vijay prativadi"));

Console.WriteLine("Press <ENTER> to terminate.");

Console.ReadLine();
announcementServiceHost.Close();

}

}
static void OnOnlineEvent(object sender, AnnouncementEventArgs e)
{

Console.WriteLine("Received an online announcement from {0}",
e.EndpointDiscoveryMetadata.Address);
Console.WriteLine("Received an online announcement from {0}", e.EndpointDiscoveryMetadata.ContractTypeNames.ToString());
Console.WriteLine("Received an online announcement from {0}", e.EndpointDiscoveryMetadata.ListenUris.ToString());
Console.WriteLine("Received an online announcement from {0}", e.EndpointDiscoveryMetadata.Version);

}

static void OnOfflineEvent(object sender, AnnouncementEventArgs e)
{
Console.WriteLine("Received an offline announcement from {0}",
e.EndpointDiscoveryMetadata.Address);
Console.WriteLine("Received an offline announcement from {0}",
e.EndpointDiscoveryMetadata.ContractTypeNames.ToString());
Console.WriteLine("Received an offline announcement from {0}", e.EndpointDiscoveryMetadata.ListenUris.ToString());
Console.WriteLine("Received an offline announcement from {0}", e.EndpointDiscoveryMetadata.Version);

}
}
}

The Output of the Application looks like this:

I hope this article is useful for you.