Add items to listbox programmatically in asp.net

In this article I am going to explain how to add items to listbox programmatically in asp.net

Implementation:

HTML Markup:

<fieldset style="width:400px">

            <legend>Add items to Listbox </legend>

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

            <br />

        Add Options: <asp:TextBox ID="txtoption" runat="server"></asp:TextBox><asp:Button ID="btnoption" runat="server" Text="btnsubmit" OnClick="btnoption_Click" />

        </fieldset>

Add items to Listbox

C# Code:

protected void btnoption_Click(object sender, EventArgs e)

    {

        ListBox1.Visible = true;

        ListBox1.Items.Add(new ListItem(txtoption.Text));

        txtoption.Text = string.Empty;

    }

VB.net Code:

Protected Sub btnoption_Click(sender As Object, e As EventArgs) Handles btnoption.Click

        ListBox1.Visible = True

        ListBox1.Items.Add(New ListItem(txtoption.Text))

        txtoption.Text = String.Empty

    End Sub