ListBox Class

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
namespace ListBoxClass
{
    public partial class Form1 : Form
    {
        ListBox listBox1 = new ListBox();
        Label label1 = new Label();
        TextBox textBox1 = new TextBox();
        Button button1 = new Button();
        Button button2 = new Button();
        public void SetupControls()
        {            
            this.ClientSize = new Size(368, 262);           
            this.FormBorderStyle = FormBorderStyle.FixedSingle;
            this.MaximizeBox = false;
            this.Text = Application.ProductName + " - " + listBox1.Items.Count.ToString() + " items";
            listBox1.Height = 225;
            listBox1.Dock = DockStyle.Top;
            listBox1.TabIndex = 1;
            listBox1.SelectedIndexChanged += new EventHandler(listBox1_SelectedIndexChanged);
            label1.Location = new Point(12, 236);
            label1.Text = "Item text:";
            label1.AutoSize = true;
            textBox1.Location = new Point(68, 233);
            textBox1.Size = new Size(123, 20);
            textBox1.TabIndex = 2;
            textBox1.TextChanged += new EventHandler(textBox1_TextChanged);
            button1.Enabled = false;
            button1.Location = new Point(197, 231);           
            button1.TabIndex = 3;
            button1.Text = "Add"; 
            button1.Click += new EventHandler(button1_Click);
           
            button2.Enabled = false;
            button2.Location = new Point(278, 231);
            button2.Size = new Size(75, 23);
            button2.TabIndex = 4;
            button2.Text = "Remove";
            button2.Click += new EventHandler(button2_Click);
        }
        public void AddControls()
        {
            this.Controls.Add(listBox1);
            this.Controls.Add(label1);
            this.Controls.Add(textBox1);
            this.Controls.Add(button1);
            this.Controls.Add(button2);
        }
        public Form1()
        {
            InitializeComponent();
            SetupControls();
            AddControls();           
        }
        private void listBox1_SelectedIndexChanged(object sender, EventArgs e)
        {
            if (listBox1.SelectedItems.Count != 0)
            {
                button2.Enabled = true;
            }
            else
            {
                button2.Enabled = false;
            }
        }
        private void textBox1_TextChanged(object sender, EventArgs e)
        {
            if (textBox1.Text != "")
            {
                button1.Enabled = true;
            }
            else
            {
                button1.Enabled = false;
            }
        }
        private void button1_Click(object sender, EventArgs e)
        {
            if (!listBox1.Items.Contains(textBox1.Text))
            {
                listBox1.Items.Add(textBox1.Text);
                this.Text = Application.ProductName + " - " + listBox1.Items.Count.ToString() + " items";
                textBox1.Text = "";
                textBox1.Focus();
            }
            else
            {
                MessageBox.Show("This item already exists!", "Warning", MessageBoxButtons.OK, MessageBoxIcon.Warning);
            }
        }
        private void button2_Click(object sender, EventArgs e)
        {
            if (MessageBox.Show("Are you sure?", "Remove item", MessageBoxButtons.YesNo, MessageBoxIcon.Question) == DialogResult.Yes)
            {
                listBox1.Items.RemoveAt(listBox1.SelectedIndex);
                this.Text = Application.ProductName + " - " + listBox1.Items.Count.ToString() + " items";
                button2.Enabled = false;
            }
        }
    }
}

Any chance of an example showing how to bind to DataAdapter please?

The ListBox uses the objects ToString() method for the display text. Override it to customize the display. Nice and simple. HOWEVER, if your ToString returns null, ListBox.Add(object) will throw an Out of Memory Exception, with a "There are too many list items" message. A GB a RAM won't help, just fix your ToString() method.

button1.Click.Add(fun e-> 

    let listBox1 = new ListBox()
    // Set the size and location of the ListBox.
    listBox1.Size <- new System.Drawing.Size(200, 100)
    listBox1.Location <- new System.Drawing.Point(10,10)
    // Add the ListBox to the form.
    form.Controls.Add(listBox1)
    // Set the ListBox to display items in multiple columns.
    listBox1.MultiColumn <- true
    // Set the selection mode to multiple and extended.
    listBox1.SelectionMode <- SelectionMode.MultiExtended
    // Shutdown the painting of the ListBox as items are added.
    listBox1.BeginUpdate()
    // Loop through and add 50 items to the ListBox.
    for x in 1..50 do
    listBox1.Items.Add("Item " + x.ToString())|>ignore
    // Allow the ListBox to repaint and display the new items.
    listBox1.EndUpdate()
    // Select three items from the ListBox.
    listBox1.SetSelected(1, true)
    listBox1.SetSelected(3, true)
    listBox1.SetSelected(5, true)
    // Display the second selected item in the ListBox to the console.
    System.Diagnostics.Debug.WriteLine(listBox1.SelectedItems.[1].ToString())
    // Display the index of the first selected item in the ListBox.
    System.Diagnostics.Debug.WriteLine(listBox1.SelectedIndices.[0].ToString()) 
    )