WCF (windows communication foundation) Service?

What is WCF (windows communication foundation) Service?

Windows Communication Foundation (Code named Indigo) is a programming platform and runtime system for building, configuring and deploying network-distributed services. It is the latest service oriented technology; Interoperability is the fundamental characteristics of WCF. It is unified programming model provided in .Net Framework 3.0. WCF is a combined feature of Web Service, Remoting, MSMQ and COM+. WCF provides a common platform for all .NET communication.

 

Advantages of WCF

1)    WCF is interoperable with other services when compared to .Net Remoting where the client and service have to be .Net.

2)    WCF services provide better reliability and security in compared to ASMX web services.

3)    In WCF, there is no need to make much change in code for implementing the security model and changing the binding. Small changes in the configuration will make your requirements.

4)    WCF has integrated logging mechanism, changing the configuration file settings will provide this functionality. In other technology developer has to write the code.

Difference between WCF and Web service

Web service is a part of WCF. WCF offers much more flexibility and portability to develop a service when comparing to web service. Still we are having more advantages over Web service; following table provides detailed difference between them.

Features	Web Service	WCF
Hosting	It can be hosted in IIS	It can be hosted in IIS, windows activation service, Self-hosting, Windows service
Programming	[WebService] attribute has to be added to the class	[ServiceContract] attribute has to be added to the class
Model	[WebMethod] attribute represents the method exposed to client	[OperationContract] attribute represents the method exposed to client
Operation	One-way, Request- Response are the different operations supported in web service	One-Way, Request-Response, Duplex are different type of operations supported in WCF
XML	System.Xml.serialization name space is used for serialization	System.Runtime.Serialization namespace is used for serialization
Encoding	XML 1.0, MTOM(Message Transmission Optimization Mechanism), DIME, Custom	XML 1.0, MTOM, Binary, Custom
Transports	Can be accessed through HTTP, TCP, Custom	Can be accessed through HTTP, TCP, Named pipes, MSMQ,P2P, Custom
Protocols	Security	Security, Reliable messaging, Transactions

A WCF Service is composed of three components parts viz,

1) Service Class - A WCF service class implements some service as a set of methods.

2) Host Environment - A Host environment can be a Console application or a Windows Service or a Windows Forms application or IIS as in case of the normal asmx web service in .NET.

3) Endpoints - All communications with the WCF service will happen via the endpoints. The endpoint is composed of 3 parts (collectively called as ABC's of endpoint) as defines below:

Address: The endpoints specify an Address that defines where the endpoint is hosted. It’s basically url.

Ex:http://localhost/WCFServiceSample/Service.svc

Binding: The endpoints also define a binding that specifies how a client will communicate with the service and the address where the endpoint is hosted. Various components of the WCF are depicted in the figure below.

• "A" stands for Address: Where is the service?
• "B" stands for Binding: How can we talk to the service?
• "C" stands for Contract: What can the service do for us?

Creating simple application using WCF

First open Visual Studio and click file --> Select New --> Website Under that select WCF Service and give name for WCF Service and click OK 

Once you created application you will get default class files including Service.cs and IService.cs

Here IService.cs is an interface it does contain Service contracts and Data Contracts and Service.cs is a normal class inherited by IService where you can all the methods and other stuff.

Now open IService.cs write the following code

[ServiceContract] public interface IService { [OperationContract] string Welcome(string Name); }

After that open Service.cs class file and write the following code 

public class Service : IService

{

public string SampleMethod(string Name)

{

return "First WCF Sample Program " + Name;

}

} 

 

 

Calling WCF Service using Console Application

To call WCF service we have many ways like using console app, windows app and web app but here I am going for console application.

Create new console app from visual studio select project type as console application gives some name as you like.

After Creation Console application now we need to add WCF reference to our console application for that right click on your windows application and select Add Service Reference

Now one wizard will open in that give your WCF service link and click Go after add your service click OK button.

After completion of adding WCF Service write the following code in Program.cs class file Main method

static void Main(string[] args) { ServiceReference1.ServiceClient objService = new ServiceClient(); Console.WriteLine("Please Enter your Name"); string Message = objService.SampleMethod(Console.ReadLine()); Console.WriteLine(Message); Console.ReadLine(); }

After that open your app.config file and check your endpoint connection for WCF Service reference that should be like this

<endpoint address=" http://localhost/WCFServiceSample/Service.svc" binding="wsHttpBinding" bindingConfiguration="WSHttpBinding_IService" contract="ServiceReference1.IService" name="WSHttpBinding_IService"> <identity> <dns value="localhost" /> </identity> </endpoint>

Now everything is ready run your application that output should be like this