Retrieving data into ComboBox using WCF Services

Introduction: Fetching data into combobox using WCF Services.

In this article, I am making a WCF service of fetching data from database into a combobox. For this purpose, read the steps carefully which are given belows:

Step 1: Open visual studio and click on file menu.

• Go to new -> project.
• New project dialog box will appear.
• Select WCF -> WCF Service Application.
• Give the name as you desire.
• Press ok as shown below on figure:

Step 2: Go to solution explorer.

• open the Iservice1.vb.
• write a code like:

Code:
 
' NOTE: You can use the "Rename" command on the "Refactor" menu to change the interface name "IService1" in both code and config file together.
<ServiceContract()> _
Public Interface IService1
 
    <OperationContract()> _
    Function show() As DataSet
 
    ' TODO: Add your service operations here

End Interface

Step 3: Now, open the Service1.svc.vb.

• write the code like:

Code:

' NOTE: You can use the "Rename" command on the "Refactor" menu to change the class name "Service1" in code, svc and config file together.
Public Class Service1
    Implements IService1
    Public Function show() As DataSet
        Dim da As New SqlDataAdapter("select * from employee", "database=vinit;server=.;uid=sa;pwd=wintellect")
        Dim ds As New DataSet()
        da.Fill(ds)
        Return ds
    End Function

End Class

Step 4: Start Debugging by pressing F5.

• A dialog box will appear i.e 'WCF Test Client'.

• Copy the highlighted address as shown below in figure:

Step 5: Open the visual studio and go to the file menu.

• Select new -> project.

• Select any type of application. Suppose we add 'Windows Form Application'.

Step 6: Go to Solution Explorer.

• Right click on 'References' and select 'Add Service Reference...'

• 'Add Service Reference' dialog box will appear.

• Paste the address which is copied in step 4.

• Press OK button.

Step 7: Now, take controls on Form design as shown in the figure:

• Write the code on 'Form1.vb' as:

Code:

Partial Public Class Form1
    Inherits Form
    Public Sub New()
        InitializeComponent()
    End Sub
 
    Private Sub comboBox1_SelectedIndexChanged(sender As Object, e As EventArgs)
 
        label2.Text = comboBox1.SelectedValue.ToString()
    End Sub
 
    Private Sub Form1_Load(sender As Object, e As EventArgs)
        Dim obj As New ServiceReference1.Service1Client()
        comboBox1.DataSource = obj.show().Tables(0)
        comboBox1.DisplayMember = "empid"
        comboBox1.ValueMember = "empname"
        label2.Text = comboBox1.SelectedValue.ToString()
    End Sub

End Class

Step 8: Now we press F5 and run this application and result shows like figure below: