Add and Delete Items in ListBox Dynamically

HTML code

Create a aspx page with a list box, text box and 2 buttons as shown below.

<div style="margin: 0 auto; text-align: center;">
        <table border="0">
            <tr>
                <td>
                    <asp:Label ID="lblfoodnames" runat="server" Text="List of Foods" Font-Bold="true"></asp:Label>
                </td>
                <td>
                    <asp:ListBox ID="lbnames" runat="server" Width="180px" BackColor="AliceBlue" Height="120px">
                    </asp:ListBox>
                </td>
                <td>
                </td>
            </tr>
            <tr>
                <td>
                </td>
                <td>
                    <asp:TextBox ID="txtadditems" Width="180px" BackColor="AliceBlue" runat="server"></asp:TextBox>
                </td>
                <td>
                    <asp:Button ID="btnaddItems" runat="server" Text="Add Food" 
                        onclick="btnaddItems_Click" />
                    <asp:Button ID="btnremoveItems" runat="server" Text="Remove Food" 
                        onclick="btnremoveItems_Click" />
                </td>
            </tr>
        </table>
    </div>

C# code In cs page add the following code for the Add Food button click event to add new items in list box.

 protected void btnaddItems_Click(object sender, EventArgs e)
    {
        // add the value from textbox to list 
        lbnames.Items.Add(txtadditems.Text);

        // clear the textbox after adding
        txtadditems.Text = "";

    }

Next for the Remove Food button add the following code

 protected void btnremoveItems_Click(object sender, EventArgs e)
    {
        // get the selected item
        ListItem selected = lbnames.SelectedItem;

        // remove the items
        lbnames.Items.Remove(selected);

    }

Now to text the code enter some values in text box and click Add Food button and see the result as shown below.

 

To remove the item from list. Select the item and click remove food button as shown below.