소스

private void txbTel_KeyPress(object sender, KeyPressEventArgs e)

{

    if (Char.IsDigit(e.KeyChar)

    || e.KeyChar ==Convert.ToInt32(Keys.Back)

    || (e.KeyChar == '-')

    )

        {

//e.Handled = false;

        }

        else

        {

            e.Handled = true; // 처리되었다실행하지말아라.

        }

    }

}

}