In this article I will explain with an example, how to bind (populate) ComboBox from Database using DataTable (DataSet) in Windows Forms using C# and VB.Net.
 
 

Database

I have made use of the following table Customers with the schema as follows.
Bind (Populate) ComboBox from Database using DataTable (DataSet) in Windows Forms using C# and VB.Net
 
I have already inserted few records in the table.
Bind (Populate) ComboBox from Database using DataTable (DataSet) in Windows Forms using C# and VB.Net
 
Note: You can download the database table SQL by clicking the download link below.
          Download SQL file
 
 

Form Design

The following Form consists of:
ComboBox – For capturing Name.
Button – The Button has assigned with Click event handler.
Bind (Populate) ComboBox from Database using DataTable (DataSet) in Windows Forms using C# and VB.Net
 
 

Namespaces

C#
using System.Data;
using System.Data.SqlClient;
 
VB.Net
Imports System.Data
Imports System.Data.SqlClient
 
 

Bind (Populate) ComboBox from Database using DataTable (DataSet)

Inside the Form1_Load event, the records from the database are fetched into a DataTable.
Once the DataTable is populated from database, a new row is inserted in First position which will act as the Default (Blank) item for the ComboBox.
C#
private void Form1_Load(object sender, EventArgs e)
{
    string constr = @"Data Source=.\SQL2014;Initial Catalog= AjaxSamples;Integrated Security=true";
    using (SqlConnection con = new SqlConnection(constr))
    {
        using (SqlDataAdapter sda = new SqlDataAdapter("SELECT CustomerId, Name FROM Customers", con))
        {
            //Fill the DataTable with records from Table.
            DataTable dt = new DataTable();
            sda.Fill(dt);
 
            //Insert the Default Item to DataTable.
            DataRow row = dt.NewRow();
            row[0] = 0;
            row[1] = "Please select";
            dt.Rows.InsertAt(row, 0);
 
            //Assign DataTable as DataSource.
            cbCustomers.DataSource = dt;
            cbCustomers.DisplayMember = "Name";
            cbCustomers.ValueMember = "CustomerId";
        }
    }
}
 
VB.Net
Private Sub Form1_Load(ByVal  sender As Object, ByVal e As EventArgs) Handles MyBase.Load
    Dim constr As String = "Data Source=.\SQL2014;Initial Catalog=AjaxSamples;Integrated Security=true"
    Using con As SqlConnection = New SqlConnection(constr)
        Using sda As SqlDataAdapter = New SqlDataAdapter("SELECT CustomerId, Name FROM Customers", con)
            'Fill the DataTable with records from Table.
            Dim dt As DataTable = New DataTable()
            sda.Fill(dt)
 
            'Insert the Default Item to DataTable.
            Dim row As DataRow = dt.NewRow()
            row(0) = 0
            row(1) = "Please select"
            dt.Rows.InsertAt(row, 0)
 
            'Assign DataTable as DataSource.
            cbCustomers.DataSource = dt
            cbCustomers.DisplayMember = "Name"
            cbCustomers.ValueMember = "CustomerId"
        End Using
    End Using
End Sub
 
 

Fetching the selected Text and Value of ComboBox

When the Submit Button is clicked, the selected Text and Value of the ComboBox is fetched and displayed using MessageBox.
C#
private void btnSubmit_Click(object sender, EventArgs e)
{
    string message = "Name: " + cbCustomers.Text;
     message += Environment.NewLine;
     message += "CustomerId: " + cbCustomers.SelectedValue;
     MessageBox.Show(message);
}
 
VB.Net
Private Sub btnSubmit_Click(ByVal sender As Object, ByVal e As EventArgs) Handles btnSubmit.Click
    Dim message As String = "Name:" & cbCustomers.Text
     message += Environment.NewLine
     message += "CustomerId:" & cbCustomers.SelectedValue
     MessageBox.Show(message)
End Sub
 
 

Screenshot

Bind (Populate) ComboBox from Database using DataTable (DataSet) in Windows Forms using C# and VB.Net
 
 

Downloads

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