C# .NET - How to bind data with ComboBox? - Asked By Eswaran Radhakrishnan on 12-Aug-08 06:46 AM

Binding to a Combobox

The Combobox doesn't have a DataMember property - instead it has a DisplayMember and ValueMember property:

The DisplayMember of a Combobox gets or sets a string that specifies the property of the data source whose contents you want to display.

The ValueMember property determines which value gets moved into the SelectedValue of the Combo Box. In the example, whenever the user selects a Customer by "Customers.CompanyName", the SelectedValue is the "Customers.CustomerID". Whenever the SelectedValue changes, the data-binding moves the new value into the Customer object.

// Setup the combobox view and display-, value member
cbCust.DataSource = dsView;
cbCust.DisplayMember = "Customers.CompanyName";
cbCust.ValueMember = "Customers.CustomerID";

also see this linke

http://www.akadia.com/services/dotnet_databinding.html

combobox1.DataSource  = ds;

combobox1.DisplayMember = "EmpName";

combobox1.ValueMember = "EmpId";

Binding to a Combobox

The Combobox doesn't have a DataMember property - instead it has a DisplayMember and ValueMember property:

The DisplayMember of a Combobox gets or sets a string that specifies the property of the data source whose contents you want to display.

The ValueMember property determines which value gets moved into the SelectedValue of the Combo Box. In the example, whenever the user selects a Customer by "Customers.CompanyName", the SelectedValue is the "Customers.CustomerID". Whenever the SelectedValue changes, the data-binding moves the new value into the Customer object.

// Setup the combobox view and display-, value member
cbCust.DataSource = dsView;
cbCust.DisplayMember = "Customers.CompanyName";
cbCust.ValueMember = "Customers.CustomerID";

Code:

SqlConnection conn = new SqlConnection(@"Data Source=.\SQLEXPRESS;AttachDbFilename=D:\ATUL\WebSite\TryOutWebsite\App_Data\Database.mdf;Integrated Security=True;User Instance=True");

SqlCommand cmd = null;

protected void Page_Load(object sender, EventArgs e)

if (!IsPostBack)

cmd = new SqlCommand();

cmd.CommandType = CommandType.Text;

cmd.CommandText = "Select * from EMP";

SqlDataAdapter da = new SqlDataAdapter(cmd);

DataSet ds = new DataSet();

GridView gv = new GridView();

DropDownList1.DataTextField = "EmpName";

DropDownList1.DataValueField = "EmpId";

protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)

Label1.Text = Convert.ToString(DropDownList1.SelectedValue);

see this example:

Imports System
Imports System.Data
Imports System.Data.OleDb
Imports System.Data.SqlClient
Imports System.Collections
Imports System.Windows.Forms
Imports System.Resources

Public Class MainClass
    Shared Sub Main()
        Dim form1 As Form = New Form1()
        Application.Run(form1)

    End Sub
End Class



Public Class Form1
    'Form level variables
    Private strConnectionString As String = _
        "Provider=Microsoft.Jet.OLEDB.4.0;" & _
        "Data Source=Employee.mdb;"

    Private objConnection As OleDbConnection
    Private objCommand As OleDbCommand
    Private objDataAdapter As OleDbDataAdapter
    Private objDataTable As DataTable

    Private Sub Form1_Load(ByVal sender As Object, _
        ByVal e As System.EventArgs) Handles Me.Load

        'Initialize the Connection object
        objConnection = New OleDbConnection(strConnectionString)

        'Initialize the Command object
        objCommand = New OleDbCommand("SELECT ID, FirstName " & _
            "FROM Employee", objConnection)

        'Initialize the DataAdapter object and set the SelectCommand property
        objDataAdapter = New OleDbDataAdapter
        objDataAdapter.SelectCommand = objCommand

        'Initialize the DataTable object
        objDataTable = New DataTable

        'Populate the DataTable
        objDataAdapter.Fill(objDataTable)

        'Bind the DataTable to the ComboBox
        ComboBox1.DataSource = objDataTable
        ComboBox1.DisplayMember = "FirstName"
        ComboBox1.ValueMember = "ID"

        'Clean up
        objDataAdapter.Dispose()
        objDataAdapter = Nothing
        objCommand.Dispose()
        objCommand = Nothing
        objConnection.Dispose()
        objConnection = Nothing
    End Sub
End Class

Go through this link:

http://www.java2s.com/Code/VB/Database-ADO.net/DatabaseDataBindingComboBox.htm

To bind a ComboBox or ListBox control

The Combobox doesn't have a DataMember property - instead it has a DisplayMember and ValueMember property:

// Setup the combobox view and display-, value member
cbCust.DataSource = dsView;
cbCust.DisplayMember = "Customers.CompanyName";
cbCust.ValueMember = "Customers.CustomerID";

also see this linke

ComboBox1.DataValueField = "rol_id";

ComboBox1.DataTextField = "rol_descr";

ComboBox1.Items.Insert(0,new ListItem("Select", "0"));

This is not the correct method, correct method is as follow,

cmbDate.ValueMember = "BATCHDATE"; 

 cmbDate.DataSource = dt_Global; -->data table name