My code:
private void clearToolStripMenuItem_Click(object sender, EventArgs e)
{
RecursiveClearTextBoxes(this.Controls);
}
private void RecursiveClearTextBoxes(Control.ControlCollection cc)
{
foreach (Control ctrl in cc)
{
TextBox tb = ctrl as TextBox;
if (tb != null)
tb.Clear();
else
RecursiveClearTextBoxes(ctrl.Controls);
}
}