public class CheckBoxItem 

public void CreateMyGcCheckedGroupBox()
{
    GcCheckedGroupBox gcCheckedGroupBox1 = new GcCheckedGroupBox();
    gcCheckedGroupBox1.Location = new Point(15, 15);
    gcCheckedGroupBox1.Text = "MyGcCheckedGroupBox";

    // Create an item.
    CheckBoxItem item = new CheckBoxItem();

    // Set the Text of CheckBoxItem.
    item.Text = "MyCheckBoxItem";

    // Set a new Font from the existing font.
    item.Font = new Font(item.Font, FontStyle.Bold);

    // Set the BackColor and ForeColor properties for CheckBoxItem.
    item.BackColor = Color.LightGreen;
    item.ForeColor = Color.LightPink;

    // Disable the item.
    item.Enabled = false;

    gcCheckedGroupBox1.LayoutSettings.LayoutMode = LayoutMode.Absolute;
    // Set the location of the item.
    item.Location = new Point(15, 15);

    // Clone an item, modify its location and change its Enabled to true to enable the UI interaction.
    CheckBoxItem clonedItem = item.Clone() as CheckBoxItem;
    clonedItem.Location = new Point(15, 40);
    clonedItem.Enabled = true;

    gcCheckedGroupBox1.Items.Add(item);
    gcCheckedGroupBox1.Items.Add(clonedItem);
    this.Controls.Add(gcCheckedGroupBox1);
}