Multiple Service Contracts in WCF Service

Objective

In this article, I will show you, how we can have multiple contracts in WCF service.

Block Diagram

Above block diagram says
1.    There are three contracts.
2.    All contracts are being implemented in same service class.
3.    Each contract is exposed on different end points.
To start with follow the below steps,

Step 1

Create a WCF Service Application.

Step 2

Already by default IService1 contract is being added. Add two more contracts. Right click on the project and select add new item and then choose Interface from Code tab.
For my purpose, I am adding two more contracts called IMyContract1 and IMyContract2.  So now there are three service contracts in my service.  They are

1.    IService1
2.    IMyContract1
3.    IMyContract2

IService1

using System;using System.Collections.Generic;using System.Linq;using System.Runtime.Serialization;using System.ServiceModel;using System.ServiceModel.Web;using System.Text;namespace MultipleEndpoints
{[ServiceContract]public interface IService1{[OperationContract]string GetMessagefromIService1();}}

IMyContract1

using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.ServiceModel; 

namespace MultipleEndpoints
{[ServiceContract]publicinterface IMyContract1{[OperationContract ]string GetMessagefromIMyContract1();}}

IMyContract2

using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.ServiceModel;namespace MultipleEndpoints
{[ServiceContract]publicinterface IMyContract2{[OperationContract]string GetMessagefromIMyContract2();}}

Step 3

Implement the contracts in same service class Service1.svc. All  the function is just returning a simple string.

Service1.svc.cs

using System;using System.Collections.Generic;using System.Linq;using System.Runtime.Serialization;using System.ServiceModel;using System.ServiceModel.Web;using System.Text;namespace MultipleEndpoints
{public class Service1 : IService1, IMyContract1, IMyContract2{public string GetMessagefromIService1(){return "Calling Default Contract IService1";}public string GetMessagefromIMyContract1(){return "Calling My Contract IMyContract1";}public string GetMessagefromIMyContract2(){return "Calling My Contract IMyContract2";}}}

 Step 4 

Now we need to configure the end points for the different contracts.  Just modify System.ServiceModel node in configuration file (Web.Config) as below 

If you see the above end points configuration, different contracts has been exposed on different endpoints.  Address of the end points is given as relative to base address. And each end point contains a unique name also.  Address is unique for each end point.

Web.Config

<?xml version="1.0"?><configuration><system.web><compilation debug="true" targetFramework="4.0" /></system.web><system.serviceModel><behaviors><serviceBehaviors><behavior name ="Mg"><serviceMetadata httpGetEnabled="true"/><serviceDebug includeExceptionDetailInFaults="false"/></behavior></serviceBehaviors></behaviors><services ><service name ="MultipleEndpoints.Service1"behaviorConfiguration ="Mg"><endpointname="firstBinding"address ="/firstContract"binding ="basicHttpBinding"contract ="MultipleEndpoints.IService1" /><endpoint name="secondBinding"address ="/secondContract"binding ="basicHttpBinding"contract ="MultipleEndpoints.IMyContract1"/><endpoint name="thirdBinding"address ="/thirdContract"binding ="basicHttpBinding"contract ="MultipleEndpoints.IMyContract2"/><endpoint contract="IMetadataExchange"binding="mexHttpBinding"address="mex" /><host><baseAddresses ><add baseAddress ="http://localhost:8180/Service1.svc"/></baseAddresses></host></service ></services></system.serviceModel><system.webServer><modules runAllManagedModulesForAllRequests="true"/></system.webServer></configuration>

Step 5

Press F5 to run the service.  Once service is up and running, we are ready to consume the service in client.

Step 6

Create a Console application as client. Add the service reference of the service.  Now you can see, there are three proxy classes have been generated by WCF. Each class is corresponding to each service contracts exposed by the service through the end points. 

You can see three service contracts have been exposed to the clients. 

Above block diagram says the all that, each contract is exposed on different end points.  And WCF created corresponding class for each contracts.

Program.cs

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


namespace ConsoleApplication1
{class Program
    {static void Main(string[] args)
        {

            Service1Client p = new Service1Client("firstBinding");
            MyContract1Client q = new MyContract1Client("secondBinding");
            MyContract2Client r = new MyContract2Client("thirdBinding");
            Console.WriteLine(p.GetMessagefromIService1());
            Console.WriteLine(q.GetMessagefromIMyContract1());
            Console.WriteLine(r.GetMessagefromIMyContract2());
            Console.Read();
              

        }
    }
}

 When you run, you will get output as 

Thanks for reading. I hope article was useful. Happy  Coding.