C#

System.Windows.Forms.CheckedListBox AvailableDataList;

private void loadDataToolStripMenuItem_Click(object sender, EventArgs e)
{
     TabPage tp = new TabPage();
     tp.Text = "Data";
     AvailableDataList = new system.Windows.Forms.CheckedListBox();
     AvailableDataList.Dock=DockStyle.Fill;
     tp.Controls.Add(AvailableDataList);
 
    for (bb = 0; bb < 8; bb++)
    {
        AvailableDataList.Items.Add("Bob");
        switch(SelectName(bb))
        {
            case false:
                AvailableDataList.SetItemChecked(bb, false);
                break;
            case true:
                AvailableDataList.SetItemChecked(bb, true);
        }
    tabControl1.TabPages.Add(tp);
}
 

private void button4_Click(object sender, EventArgs e)
{
    if(AvailableDataList != null)
        label1.text = AvailableDataList.Items.Count;
}