private void AddControls_Click(object sender, EventArgs e)
{
Button newButton = new Button { Text = "New Button" };
CheckBox newCheckBox = new CheckBox { Text = "New CheckBox", ThreeState = true };
List<Control> lst = new List<Control>();
lst.Add(newButton);
lst.Add(newCheckBox);
this.Controls.AddRange(lst.ToArray());
}