Bind comma separated values to listbox in asp.net

In this article I am going to explain how to Bind comma separated values to listbox in asp.net in ASP.Net using C# and VB.net

In the previous article I have explained how to get comma separated values (data) from databaseand bind to checkboxlist in ASP.Net using C# and VB.net, how to insert multipleselected items of Listbox to database as comma separated in ASP.Net using C#and VB.net and how to generate alphabets A to Z in asp.net, VB.net.

Implementation:

I have created a table Tb_Technology:

Id	int
Technology	varchar(50)

Insert the dummy data into table:

 Insert into Tb_Technology(Technology) values('Asp.net,Php,Java')

Add a webform to project. Drag and drop the require control (Listbox) from toolbox to webform.

HTML Markup:

  <fieldset style="margin-left: 40px;width:30%">

    <legend><strong>Bind comma separated values to CheckBoxList</strong></legend>

    <table>

    <tr><td>Select Technology :</td><td>

        <asp:ListBox ID="ListBox1" runat="server" SelectionMode="Multiple"></asp:ListBox>

    </td></tr>

    </table>

    </fieldset>

Add the namespace

C# code:

using System.Data;

using System.Data.SqlClient;

using System.Configuration;

VB.net code

Imports System.Data

Imports System.Data.SqlClient

Imports System.Configuration

Create sqlconnection

C# code:

SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["connection"].ToString());

VB.net code

Dim con As New SqlConnection(ConfigurationManager.ConnectionStrings("connection").ToString())

Bind the Listbox

Create a method to bind the comma separated text to Listbox and call it on page load.

C# code:

protected void Page_Load(object sender, EventArgs e)

    {

        if (!IsPostBack)

        {

            BindListBox();

        }

    }

    public void BindListBox()

    {

        try

        {

            SqlDataAdapter adp = new SqlDataAdapter("Select * from Tb_Technology", con);

            DataTable dt = new DataTable();

            adp.Fill(dt);

            if (dt.Rows.Count > 0)

            {

                string listboxvalues = dt.Rows[0]["Technology"].ToString();

                foreach (string tech in listboxvalues.Split(','))

                {

                    ListItem items = new ListItem();

                    items.Text = tech;

                    items.Value = tech;

                    ListBox1.Items.Add(items);

                }

            }

        }

        catch (Exception ex)

        { }      

    }

VB.net code

Protected Sub Page_Load(sender As Object, e As System.EventArgs) Handles Me.Load

        If Not IsPostBack Then

            BindListBox()

        End If

    End Sub

    Public Sub BindListBox()

        Try

            Dim adp As New SqlDataAdapter("Select * from Tb_Technology", con)

            Dim dt As New DataTable()

            adp.Fill(dt)

            If dt.Rows.Count > 0 Then

                Dim listboxvalues As String = dt.Rows(0)("Technology").ToString()

                For Each tech As String In listboxvalues.Split(","c)

                    Dim items As New ListItem()

                    items.Text = tech

                    items.Value = tech

                    ListBox1.Items.Add(items)

                Next

            End If

        Catch ex As Exception

        End Try

    End Sub