Create and Consume WCF services in VB.NET

What is WCF?

WCF is a unification technology, which unites .Net Remoting, MSMQ, Web Services and COM+ technologies.

WCF provides a runtime environment for your services, enabling you to expose CLR types as services and to consume other services as CLR types.

Creating WCF Service:

Open Visual Studio 2008/2010. Click on File menu -> New -> Project ->WCF Service Application. Change the name as "WCFService" then click Ok button.

Delete auto generated files IService1.cs and Service1.svc and create new (right click on WCFService project and select Add -> New Item -> WCF Service). Rename service as "UserService".

Now add an Entity Data Model in your project to communicate with database.

Service Code

Replace interface IUserService with the code given below :

Imports System.ServiceModel

<ServiceContract()>
Public Interface IUserService

    <OperationContract()>
    Sub DoWork()

    <OperationContract()> 
    Function Authenticate(ByVal UserName As String, ByVal A_CryptKey As String) As String

    <OperationContract()>
    Function GetApprovedUser() As DataTable
End Interface

Replace UserService class code with the code given below :

Public Class UserService
    Implements IUserService

    Public Sub DoWork() Implements IUserService.DoWork
    End Sub

    Public Function Authenticate(ByVal UserName As String, ByVal A_CryptKey As String) As String Implements IUserService.Authenticate
        Using Context = New UserServiceEntities()
            Dim user = Context.Users.Where(Function(c) c.UserName = UserName AndAlso c.A_CryptKey = A_CryptKey).FirstOrDefault()
            If user IsNot Nothing Then
                Return Convert.ToString(user.UserID)
            Else
                Return String.Empty
            End If
        End Using

    End Function

    Public Function GetApprovedUser() As List(Of User) Implements IUserService.GetApprovedUser
        Using Context = New UserServiceEntities()
            Dim user As New List(Of User)()
            user = Context.Users.Where(Function(c) c.IsApproved = True).ToList()
            Return user
        End Using
    End Function

End Class

Service configuration

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <system.web>
    <compilation debug="true" strict="false" explicit="true" targetFramework="4.0">
      <assemblies>
        <add assembly="System.Data.Entity, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5ccreate-and-consume-wcf-services-in-VB-Net34e089" />
      </assemblies>
    </compilation>
  </system.web>
  <system.serviceModel>
    <behaviors>
      <serviceBehaviors>
        <behavior>
          <!-- 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" />
  </system.serviceModel>
  <system.webServer>
    <modules runAllManagedModulesForAllRequests="true" />
  </system.webServer>
  <connectionStrings>
    <add name="UserServiceEntities" connectionString="metadata=res://*/Model1.csdl|res://*/Model1.ssdl|res://*/Model1.msl;provider=System.Data.SqlClient;provider connection string=&quot;Data Source=MANDR-PC;Initial Catalog=UserService;User ID=sa;Password=pass;MultipleActiveResultSets=True&quot;" providerName="System.Data.EntityClient" />
  </connectionStrings>
</configuration>

Consuming WCF Service:

Now right click on UserService.svc and select "View in Browser". it will show a browser with service url. Copy that url



Now right click on WCFClient project select "Add Service Reference" and paste copied url in Address section of "Add Service Reference" dialog box and click on Go button and rename Namespace as "UserService" and click ok button.



WCF Client code

Imports Client.UserService

Public Class _Default
    Inherits System.Web.UI.Page

    Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        Dim proxy As New UserServiceClient()

        Dim User As String = proxy.Authenticate("Mukesh", "X%AY#$tZ")

        ' objdt = proxy.GetApprovedUser()

        proxy.Close()
    End Sub
 
End Class

Client side configuration

<system.serviceModel>
    <bindings>
      <basicHttpBinding>
        <binding name="BasicHttpBinding_IUserService" closeTimeout="00:01:00"
          openTimeout="00:01:00" receiveTimeout="00:10:00" sendTimeout="00:01:00"
          allowCookies="false" bypassProxyOnLocal="false" hostNameComparisonMode="StrongWildcard"
          maxBufferSize="65536" maxBufferPoolSize="524288" maxReceivedMessageSize="65536"
          messageEncoding="Text" textEncoding="utf-8" transferMode="Buffered"
          useDefaultWebProxy="true">
          <readerQuotas maxDepth="32" maxStringContentLength="8192" maxArrayLength="16384"
            maxBytesPerRead="4096" maxNameTableCharCount="16384" />
          <security mode="None">
            <transport clientCredentialType="None" proxyCredentialType="None"
              realm="" />
            <message clientCredentialType="UserName" algorithmSuite="Default" />
          </security>
        </binding>
      </basicHttpBinding>
    </bindings>
    <client>
      <endpoint address="http://localhost:53820/UserService.svc" binding="basicHttpBinding"
        bindingConfiguration="BasicHttpBinding_IUserService" contract="UserService.IUserService"
        name="BasicHttpBinding_IUserService" />
    </client>
  </system.serviceModel>