Listbox Control in ASP.NET

The ListBox in ASP.NET control provides a means to display a list of selectable items on a web page. There are several methods and properties available for adding items and customizing the behavior of the ListBox control:

Adding Items

  1. The Add method is used to append items to the end of an unsorted ListBox control.
  2. The Insert method allows you to specify the position where the item should be inserted within the ListBox.

Selection Mode

  1. The ListBox control supports both single and multiple item selection modes.
  2. To enable multiple item selection, you can set the SelectionMode property to ListSelectionMode.Multiple. This allows users to select multiple items simultaneously by holding down the Ctrl or Shift key.
ListBox1.SelectionMode = ListSelectionMode.Multiple
ListBox1.SelectionMode = System.Web.UI.WebControls.ListSelectionMode.Multiple;

The following ASP.NET program add seven days in a week to the ListBox in the load event and display the selected item in the label.

listbox-control Default.aspx
<html xmlns=""> <head id="Head1" runat="server"> <title>Untitled Page</title> </head> <body> <form id="form1" runat="server"> <div> <asp:ListBox ID="ListBox1" runat="server"></asp:ListBox>   <asp:Button ID="Button1" runat="server" Text="Button" onclick="Button1_Click" /> <br /> <asp:Label ID="Label1" runat="server" Text="Label"></asp:Label> </div> </form> </body> </html>
Full Source | C#
using System; public partial class _Default : System.Web.UI.Page { protected void Page_Load(object sender, EventArgs e) { ListBox1.Items.Add("Sunday"); ListBox1.Items.Add("Monday"); ListBox1.Items.Add("Tuesday"); ListBox1.Items.Add("Wednesday"); ListBox1.Items.Add("Thursday"); ListBox1.Items.Add("Friday"); ListBox1.Items.Add("Saturday"); } protected void Button1_Click(object sender, EventArgs e) { Label1.Text = "You selected : " + ListBox1.SelectedItem.ToString(); } }
Full Source | VB.NET
Partial Class _Default Inherits System.Web.UI.Page Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load ListBox1.Items.Add("Sunday") ListBox1.Items.Add("Monday") ListBox1.Items.Add("Tuesday") ListBox1.Items.Add("Wednesday") ListBox1.Items.Add("Thursday") ListBox1.Items.Add("Friday") ListBox1.Items.Add("Saturday") ListBox1.SelectionMode = ListSelectionMode.Multiple End Sub Protected Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click Label1.Text = "you selected : " & ListBox1.SelectedItem.ToString End Sub End Class


The ListBox control is commonly used in scenarios where users need to choose items from a predefined list, such as selecting multiple categories, choosing preferences, or picking items from a list of options. Its flexibility and customization options make it a valuable tool for enhancing user interactivity and facilitating data selection in ASP.NET applications.