How can I iterate through all checkboxes on a form?

foreach(Control c in this.Controls)
{
   if(c is CheckBox)
   {
   // Do stuff here ;]
   }
}

I use a simple extension method that will work for any control type:

  public static IEnumerable<T> AllControls<T>(this Control startingPoint) where T : Control
  {
     bool hit = startingPoint is T;
     if (hit)
     {
        yield return startingPoint as T;
     }
     foreach (var child in startingPoint.Controls.Cast<Control>())
     {
        foreach (var item in AllControls<T>(child))
        {
           yield return item;
        }
     }
  }

Then, you can use it like so:

var checkboxes = control.AllControls<CheckBox>();

Using IEnumerable lets you choose how to store the results, and also lets you use linq:

var checkedBoxes = control.AllControls<CheckBox>().Where(c => c.Checked);

If it is Windows Forms, you can try something like this:

private void button1_Click(object sender, EventArgs e)
{
    Dictionary<string, bool> checkBoxes = new Dictionary<string, bool>();
    LoopControls(checkBoxes, this.Controls);
}

private void LoopControls(Dictionary<string, bool> checkBoxes, Control.ControlCollection controls)
{
    foreach (Control control in controls)
    {
        if (control is CheckBox)
            checkBoxes.Add(control.Name, ((CheckBox) control).Checked);
        if (control.Controls.Count > 0)
            LoopControls(checkBoxes, control.Controls);
    }
}

Remember that container controls can contain children, so you might want to check those too.

Like this, maybe (if it's in Windows Forms):

foreach(var checkBox in myForm.Controls.OfType<CheckBox>())
{   
   //Do something.
}

When they are created, get a list of references to the values, and then you can iterate over the list.