C#

private TimeSpan SubTime(DateTime dt1, DateTime dt2)
{
    // Substracts dt1 from dt2
    TimeSpan ts = TimeSpan.Parse(dt2.ToString("H:mm:ss"));
    return ts.Subtract(TimeSpan.Parse(dt1.ToString("H:mm:ss")));
}

public enum BBB { Vall, Val2, val3 }

public static BBB next(BBB val) { return val+1; } 

private void checkbox1_CheckedChanged(object sender, System.EventArgs e)
{
   rbutton=true;
}

private void checkbox1_CheckedChanged(object sender, System.EventArgs e)
{
   if(checkbox1.Checked)
   {
      rbutton=true;
   }
   else
   {
      rbutton=false;
   }
}

private void checkbox1_CheckedChanged(object sender, System.EventArgs e)
{
   rbutton = this.checkbox1.Checked;
}

rbutton = checkbox1.Checked;

<br />
foreach(Control control in this.Controls)<br />
{<br />
	// Do something<br />
}<br />
<br />

private void IterateControls(Control c)
{
    if (c.Controls.Count > 0)
    {
        foreach (Control child in c.Controls)
        {
            IterateControls(child);
        }
    }
    // Do something
}
.
.
.
IterateControls(this)

if (c is TextBox)
{
    TextBox tb = (TextBox)c;
    // do your printing
}

TextBox tb = c as TextBox
if(tb != null)
{
  MessageBox.Show(tb.text);
}

foreach(Control control in Controls)
{
	TextBox textBox = control as TextBox;
	if(textBox != null)
	{
		MessageBox.Show(textBox.Name + ":" + textBox.Text);	
	}
}