WCF Notes(Contract)

Contract

Collection of operation that specifies what the endpoint will communicate with outside world. Usually name of the Interface will be mentioned in the Contract, so the client application will be aware of the operations which are exposed to the client. Each operation is a simple exchange pattern such as one-way, duplex and request/reply.

Below figure illustrate the functions of Endpoint

Example for End Points

Endpoints will be mentioned in the web.config file on the created service.

<system.serviceModel>

<services>

      <service name="MathService"

        behaviorConfiguration="MathServiceBehavior">

       <endpoint

         address="http://localhost:8090/MyService/MathService.svc" contract="IMathService"

          binding="wsHttpBinding"/> 

      </service>

    </services>

    <behaviors>

      <serviceBehaviors>

        <behavior name="MathServiceBehavior">

          <serviceMetadata httpGetEnabled="True"/>

          <serviceDebug includeExceptionDetailInFaults="true" />

        </behavior>

      </serviceBehaviors>

    </behaviors>

  </system.serviceModel>

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	[ServiceContraact] 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