• Download WCF - 109.34 KB

What is WCF ? 

Windows Communication foundation API allows to build distributed architecture in such manner that once created service code can be utilize by the in-house application which using tcp/ip to communicate, web application using http protocol to communicate to web services, application using msmq. WCF Services also works with the application developed other than .net framework.

Create WCF Service 

Follow the below listed step to create Service 

Step 1: 

Create service from the Visual Studio select the go to c# or vb than select project type WCF Service library or WCf service website project template.

the first one create the *.dll and app.config file for after the compilation which you can than use in your host application and expose the service to clients.

the second one create the project with the proper web.config file and *.svc file which is get hosted on IIS via virtual directly and service get explose to client via HTTP protocol. so by that service can not be expose to tcp client. The benefit of this option is no need to create host application you can directly host it on iis via virtual directory. For this discussion first I am creating WCF service library and than I am going to discuss about iis deployment also.

Step 2: 

Create contract by specifing proper attributes. This contract tells the client what are the method get expose by the service and custom type expose by the service. You can decorate your contract by the list of attribute in System.ServiceModel namespace. you can create you own files or after selecting proper project type its create two files for you Iservcie.cs and Service.cs. If you are going to create your own files its recommanded that you can create you interface and implement it in your class. 

[ServiceContract] - defines the interface participate in provided service.

[ServiceContract]
public interface IService1
{
....
}

[OperationContract] - defines the method going to be expose by the service.

[OperationContract]
string GetData(int value);

[DataMember] - defines the property expose via service.

[DataMember]
public bool BoolValue
{
  get { return boolValue; }
  set { boolValue = value; }
}

[DataContract] - defines the custom data type expose via service.

[DataContract]
public class CompositeType
{
...
}

After you done with the creation of the web service you code should look as below 

Library app.config file 

This file contains infomation about the metadata exchange defines endpoint of metadata. its also contains information about the endpoints where client talk with service. Endpoints are ABC means Address, Binding and Contract. as you see in above config file service expose for tcp communication by following line

 <system.serviceModel>
    <services>
      <service name="WcfServiceLibrary.Service1" behaviorConfiguration="WcfServiceLibrary.Service1Behavior">
        <host>
          <baseAddresses>
            <add baseAddress = "http://localhost:8080/Service1/" />
          </baseAddresses>
        </host>
        <!-- Service Endpoints -->
        <!-- Unless fully qualified, address is relative to base address supplied above -->
        <endpoint address="net.tcp://localhost:9000/myservice" binding="netTcpBinding" contract="WcfServiceLibrary.IService1">
         
        </endpoint>
        <endpoint address ="" binding="wsHttpBinding" contract="WcfServiceLibrary.IService1">
          <!--
              Upon deployment, the following identity element should be removed or replaced to reflect the
              identity under which the deployed service runs.  If removed, WCF will infer an appropriate identity
              automatically.
          -->
          <identity>
            <dns value="localhost"/>
          </identity>
        </endpoint>
        <!-- Metadata Endpoints -->
        <!-- The Metadata Exchange endpoint is used by the service to describe itself to clients. -->
        <!-- This endpoint does not use a secure binding and should be secured or removed before deployment -->
        <endpoint address="mex" binding="mexHttpBinding" contract="IMetadataExchange"/>
      </service>
    </services>
    <behaviors>
      <serviceBehaviors>
        <behavior name="WcfServiceLibrary.Service1Behavior">
          <!-- 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>
  </system.serviceModel>

Binding details : http://www.c-sharpcorner.com/UploadFile/pjthesedays/bindwcf05032009012251AM/bindwcf.aspx 

IService.Cs file 

Service.cs 

Hosting WCF Service

• Self Host
• IIS hosting 
• Windows service
• WAS

Demo of Self hosting and IIS hosting. 

Self hosting  

Step 1:   

Create new project >> Class Library >> name this project as Host

Step 2:   

Add referance to the host application   Right click on Referance >> Add Referance

Step 3: 

After adding referance to the host application to expose webservice for client to consume as you see below line of the code create the object of the host and which is of type Service1 Which we created in the WCF Service library project

using (System.ServiceModel.ServiceHost host = new System.ServiceModel.ServiceHost(typeof(Service1)))
            {
            }

as you can see we used using block over so that it depose host object when we close application. 

Step 4: 

To start the service to hadle request coming form the client of ther service  you need to call open method         

host.Open();

and to stop receiving request you need to call close method        

Host.cs 

namespace HostApp
{
    class Program
    {
        static void Main(string[] args)
        {
            using (System.ServiceModel.ServiceHost host = new System.ServiceModel.ServiceHost(typeof(Service1)))
            {
                host.Open();


                Console.WriteLine("Service started. press any key to stop it");
                Console.ReadLine();


                host.Close();
            }
        }
    }
}

IIS hosting

1. To host same WCF library in your application create WCF Web application project using WCF web application template as we discuss in start.
2. Delete the files created in the IService.cs and Service.cs file from App_Code folder
3. Include WCF library *.dll file which we created. 
4. Open Service.svc file and modify the single line in it 

<%@ ServiceHost Language="C#" Debug="true" Service="WcfServiceLibrary.Service1" %>

5. Change the web service WEB.Config file to to expose service to client. i.e you need to create Same element as listed above in in the app.config file of service library.   

Consuming WCF Service  

Step 1:  

Create new project >> Class Library >> name this project as Client as we created Host application      If you want to consume webservice hosted in you web application start directly for the 2 step listed below.  

Step 2:   

Add Service Referance to the client by Right click on project >> Add Service Referance

which atomatically create the proxy files to consume web service. or Make use of ServiceModel Metadata Utility Tool (Svcutil.exe)  the is command-line tool to generate proxy code from metadata.

    svcutil /t:code http://<service_url> /out:<file_name>.cs /config:<file_name>.config   

Step 3:    

To send request to service form the client

            ServiceReference1.Service1Client client =  new Client.ServiceReference1.Service1Client();
            Console.WriteLine(client.GetData(5));
            Console.ReadLine();
            client.Close();

So as you see in above code you need to create object of Service1Client and than you can easily call the method expose by the Service. If you want to see the auto-generated code press F12 on the Service1Client it show the proxy code to you. 

Summary  

As you follow the process listed process step by step its quite easy to create, consume and host WCF Service.