Developing a WCF Service Library and Hosting it as WCF Web Service Using VS2K8

In this article, we will focus on developing a Windows Communication Foundation (WCF) library, turning it to a WCF web service, hosting it on an IIS web server and finally test it by developing a simple WCF client using Windows Forms. This article can serve as an excellent walkthrough resource for beginners.

Contributed by Jagadish Chaterjee
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October 01, 2007

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Creating a Windows Communication Foundation (WCF) Service Library

The following are the steps necessary to create a WCF Service Library:

Open Microsoft Visual Studio 2008 Beta 2.
Go to File || New Project.
In the "New Project" dialog box, open "Visual Basic" project types and select WCF. The respective templates for WCF will be shown on the right side.
Select the "WCF Service Library" template.
Provide "WCFSampleService" as the name and provide the proper path as the location.
Make sure that ".NET Framework 3.5" is selected at the top.
Once everything looks like the following (fig 01), click OK.
Rename "IService1.vb" to "IEmpService.vb."
Rename "Service1.vb" to "EmpService.vb."
Add a reference to "System.Configuration" as shown below (fig 02).

Figure 01

Figure 02

Creating a Windows Communication Foundation (WCF) Service Library: source code

Once the project is created (as shown above), modify "IEmpService.vb" to match the following:

<ServiceContract()> _

Public Interface IEmpService

<OperationContract()> _

Function GetNames() As List(Of String)

<OperationContract()> _

Function GetEmployeeInfo(ByVal EmpNo As Integer) As Employee

End Interface

<DataContract()> _

Public Class Employee

Private _Empno As Integer

Private _Ename As String

Private _Sal As Double

Private _Deptno As Integer

<DataMember()> _

Public Property Empno() As Integer

Get

Return _Empno

End Get

Set(ByVal value As Integer)

_Empno = value

End Set

End Property

<DataMember()> _

Public Property Ename() As String

Get

Return _Ename

End Get

Set(ByVal value As String)

_Ename = value

End Set

End Property

<DataMember()> _

Public Property Sal() As Double

Get

Return _Sal

End Get

Set(ByVal value As Double)

_Sal = value

End Set

End Property

<DataMember()> _

Public Property Deptno() As Integer

Get

Return _Deptno

End Get

Set(ByVal value As Integer)

_Deptno = value

End Set

End Property

End Class

Modify "EmpService.vb" to match the following:

Imports System.Data.SqlClient

Imports System.Data

Imports System.Configuration

Public Class EmpService

Implements IEmpService

Public Function GetEmployeeInfo(ByVal EmpNo As Integer) As Employee Implements IEmpService.GetEmployeeInfo

Using cn As New SqlConnection(ConfigurationManager.ConnectionStrings("cnNorthwind").ConnectionString)

Using cmd As New SqlCommand("SELECT empno,ename,sal,deptno FROM dbo.emp WHERE empno=" & EmpNo, cn)

cmd.Connection.Open()

Using rdr As SqlDataReader = cmd.ExecuteReader

If rdr.Read() Then

Return New Employee With {.Empno = rdr(rdr.GetOrdinal("Empno")), .Ename = rdr(rdr.GetOrdinal("Ename")) & "", .Sal = rdr(rdr.GetOrdinal("sal")) & "", .Deptno = rdr(rdr.GetOrdinal("Deptno")) & ""}

Else

Return Nothing

End If

End Using

cmd.Connection.Close()

End Using

End Function

Public Function GetNames() As System.Collections.Generic.List(Of String) Implements IEmpService.GetNames

Dim EmployeeNames As New List(Of String)

Using cn As New SqlConnection(ConfigurationManager.ConnectionStrings("cnNorthwind").ConnectionString)

Using cmd As New SqlCommand("SELECT ename FROM dbo.emp", cn)

cmd.Connection.Open()

Using rdr As SqlDataReader = cmd.ExecuteReader

If rdr.HasRows Then

While rdr.Read

EmployeeNames.Add(rdr(rdr.GetOrdinal("ename")))

End While

Return EmployeeNames

Else

Return Nothing

End If

End Using

cmd.Connection.Close()

End Using

End Function

End Class

Creating a Windows Communication Foundation (WCF) Service Library: application configuration

As we created a WCF Service Library (instead of a WCF Service Application), Visual Studio adds an "app.config" file (as opposed to a "web.config" as it would with a WCF Service Application) to the solution. Modify "app.config" to match the following:

<system.serviceModel>

<host>

</baseAddresses>

</host>

</service>

</services>

<!-- To avoid disclosing metadata information,

set the value below to false and remove the metadata endpoint above before deployment -->

<!-- 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 -->

</behavior>

</serviceBehaviors>

</behaviors>

</binding>

</wsHttpBinding>

</bindings>

</system.serviceModel>

Turning a Windows Communication Foundation (WCF) Service Library into a WCF Service Application (web service)

In the previous section, we worked with "app.config" to configure the WCF Service Library. To turn a WCF service library into WCF service application (or WCF Web Service), the first step is to add "web.config" to the solution and make modifications to the file to match the following (look for the "added by me" comments):

<?xml version="1.0"?>

</configSections>

</Services>

</WorkflowRuntime>

</connectionStrings>

<system.serviceModel>

<host>

</baseAddresses>

</host>

</service>

</services>

</behavior>

</serviceBehaviors>

</behaviors>

</binding>

</wsHttpBinding>

</bindings>

</system.serviceModel>

<system.web>

</httpModules>

</system.web>

</configuration>

Once the "web.config" is added, the second step is to add an "EmpService.svc" file to the solution. Just add a text file (using "add new item") named "EmpService.svc" as shown below (fig 03).

Figure 03

Copy the following to "EmpService.svc."

<%@ ServiceHost Service="WCFSampleService.EmpService" %>

<%@ Assembly Name="WCFSampleService" %>

Once the service file is added, the final step is to change the "build output path" of the project to "bin" (as shown below in fig 04):

Figure 04

Close all tabbed windows of Visual Studio (I suspect it could be a bug as it could not compile properly on my machine, without closing all windows) and build the solution.

Deploying and Hosting a WCF Service application (WCF web service)

Once the solution is built successfully, we need to deploy/host it on IIS. Let us start with creating a Virtual Directory in IIS to host our solution. Go through the following steps to create the same in the simplest manner:

Go to the application folder (not the solution folder), right click on it and then click on "Properties" (fig 05).
Switch to the "Security" tab and make sure that all privileges are provided for both the "ASP.NET machine account" and the "NETWORK SERVICE" accounts (fig 06).
Switch to "Web Sharing" and click on "Share this folder" (fig 07).
Accept the "default alias" ("WCFSampleService") as follows (fig 08) and click OK twice (to apply all the properties).

Figure 05

Figure 06

Figure 07

Figure 08

Deploying and Hosting WCF Service application (WCF web service), continued

Open IIS (Start || Administrative Tools || Internet Information Services Manager), and then open "Default Web Site." You should see the "WCFSampleService" configured as a web application.

Right click on "WCFSampleService" and go to "Properties" (fig 09).
Switch to the "ASP.NET" tab and select the ASP.NET version "2.0.50727" (fig 10).
Switch to "Directory Security," click on "Edit" of "Authentication and Access control," make "Enable anonymous access" checked (fig 11) and click OK twice to apply all the properties.
If the solution is configured, built and hosted properly, you should be able to access the web service from the URL http://localhost/WCFSampleService/EmpService.svc and the output should look like the following (fig 12).

Figure 09

Figure 10

Figure 11

Figure 12

Testing the WCF Web Service: creating the WCF Client using Windows Forms

To test the WCF web service created in previous sections, we need to develop a WCF client. In this case, for simplicity, I would like to work with Windows Forms.

Open a new Visual Studio environment, create a new project, select "Windows Forms Application" as the template, provide the name "WCFSampleClient" and hit OK (fig 13).

Figure 13

Design a form which looks like the following (fig 14):

Figure 14

Add a reference to WCF Service by right clicking on project and selecting "Add Service Reference" (fig 15).

Figure 15

Provide the previously created WCF Web Service URL as http://iisservername/WCFSampleService/EmpService.svc?wsdl and click "Go." Once it is found, designate the namespace as "EmpService" and hit OK (fig 16).

Figure 16

Testing the WCF Web Service: source code

For the Windows form previously created, make modifications to the existing code so it matches with the following:

Imports System.ServiceModel

Public Class Form1

Private Sub btnSearch_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnSearch.Click

Dim proxy As New EmpService.EmpServiceClient("WSHttpBinding_IEmpService")

Dim objEmp As EmpService.Employee = proxy.GetEmployeeInfo(Me.txtEmpno.Text)

proxy.Close()

With objEmp

Me.txtEname.Text = .Ename

Me.txtSal.Text = .Sal

Me.txtDeptno.Text = .Deptno

End With

End Sub

Private Sub btnGetAllNames_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnGetAllNames.Click

Dim proxy As New EmpService.EmpServiceClient("WSHttpBinding_IEmpService")

Me.lstNames.DataSource = proxy.GetNames

proxy.Close()

End Sub

End Class

Finally, hit F5 to execute and test the application (which accesses and retrieves information from the WCF web service hosted earlier). If everything works fine, you should be able see the output as follows (fig 17):