C#

using System;
using System.Collections;
using System.Drawing;
using System.Windows.Forms;
 
class CheckBoxManager
{
  ArrayList cbs;
  bool changing = false;
 
  public CheckBoxManager()
  {
    cbs = new ArrayList();
  }
 
  public void Add(CheckBox cb)
  {
    if (cb == null) throw new ArgumentNullException("cb");
    cbs.Add(cb);
    cb.CheckedChanged += new EventHandler(OnCheckChanged);
  }
 
  public void AddRange(IEnumerable cbs)
  {
    if (cbs == null) throw new ArgumentNullException("cbs");
    foreach (object obj in cbs)
    {
      CheckBox cb = obj as CheckBox;
      if (cb != null) Add(cb);
    }
  }
 
  void OnCheckChanged(object sender, EventArgs e)
  {
    // Don't run if we're current changing the Checked property
    // for each CheckBox.
    if (changing) return;
    else changing = true;
 
    foreach (CheckBox cb in cbs)
    {
      if (sender != cb) cb.Checked = false;
    }
 
    changing = false;
  }
}
 
class Test : Form
{
  static void Main()
  {
    Application.Run(new Test());
  }
 
  Test()
  {
    CheckBoxManager group0 = new CheckBoxManager();
    CheckBoxManager group1 = new CheckBoxManager();
    int top = 8;
 
    for (int i = 0; i < 10; i++)
    {
      bool isgroup0 = i % 2 == 0;
 
      CheckBox cb = new CheckBox();
      if (isgroup0) group0.Add(cb);
      else group1.Add(cb);
      Controls.Add(cb);
 
      cb.Text = string.Format("CheckBox{0} (Group {1})", i, i % 2);
      cb.Top = top;
      cb.Left = 8;
      cb.Width = 200;
      top = cb.Bottom + 8;
    }
 
    Height = SystemInformation.CaptionHeight + top;
    Text = "CheckBoxManager Example";
  }
}

Pen p = new Pen( Color.Blue );<br />
<br />
p.EndCap = System.Drawing.Drawing2D.LineCap.Triangle<br />