private void txbUsername_KeyPress(object sender, KeyPressEventArgs e) { if (!char.IsLetterOrDigit(e.KeyChar) && !validatorUtils.IsSpecialCharacter(e.KeyChar) && e.KeyChar != (char)Keys.Back || validatorUtils.IsLetterWithAccent(e.KeyChar) || e.KeyChar == 'ª' || e.KeyChar == 'º') { e.Handled = true; } }