Display ASP.Net ListBox selected Text in Label using C# and VB.Net

Hi rakesh.g11411,

Please refer below sample.

Database

For this example I have used of Northwind database that you can download using the link given below.

Download Northwind Database

HTML

<asp:ListBox ID="lstCustomers" runat="server" Height="100px" Width="203px" 
    OnSelectedIndexChanged="lstCustomers_SelectedIndexChanged"  AutoPostBack="true" ></asp:ListBox>
<br />
<br />
    Selected Item:
<br />
<asp:Label ID="lblEvents" runat="server" ></asp:Label>

Namespaces

C#

using System.Configuration;
using System.Data;
using System.Data.SqlClient;

VB.Net

Imports System.Configuration
Imports System.Data
Imports System.Data.SqlClient

Code

C#

protected void Page_Load(object sender, EventArgs e)
{
    if (!this.IsPostBack)
    {
        string constr = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
        using (SqlConnection con = new SqlConnection(constr))
        {
            using (SqlCommand cmd = new SqlCommand("SELECT TOP 5 CustomerID, ContactName FROM Customers"))
            {
                cmd.CommandType = CommandType.Text;
                cmd.Connection = con;
                con.Open();
                lstCustomers.DataSource = cmd.ExecuteReader();
                lstCustomers.DataTextField = "ContactName";
                lstCustomers.DataValueField = "CustomerID";
                lstCustomers.DataBind();
                con.Close();
            }
        }
    }
}
protected void lstCustomers_SelectedIndexChanged(object sender, EventArgs e)
{
    lblEvents.Text = lstCustomers.SelectedItem.Text;
    lstCustomers.Items.FindByText(lblEvents.Text).Selected = true;
}

VB.Net

Protected Sub Page_Load(sender As Object, e As EventArgs) Handles Me.Load
    If Not Me.IsPostBack Then
        Dim constr As String = ConfigurationManager.ConnectionStrings("constr").ConnectionString
        Using con As SqlConnection = New SqlConnection(constr)
            Using cmd As SqlCommand = New SqlCommand("SELECT TOP 5 CustomerID, ContactName FROM Customers")
                cmd.CommandType = CommandType.Text
                cmd.Connection = con
                con.Open()
                lstCustomers.DataSource = cmd.ExecuteReader()
                lstCustomers.DataTextField = "ContactName"
                lstCustomers.DataValueField = "CustomerID"
                lstCustomers.DataBind()
                con.Close()
            End Using
        End Using
    End If
End Sub

Protected Sub lstCustomers_SelectedIndexChanged(ByVal sender As Object, ByVal e As EventArgs)
    lblEvents.Text = lstCustomers.SelectedItem.Text
    lstCustomers.Items.FindByText(lblEvents.Text).Selected = True
End Sub

Screenshot