private void writeIpAddrToTextFile(string ipaddress) { if (kryptonComboBoxControllerIp.Items.Contains(ipaddress)) { kryptonComboBoxControllerIp.Items.Remove(ipaddress); } kryptonComboBoxControllerIp.Items.Insert(0, ipaddress); kryptonComboBoxControllerIp.SelectedIndex = 0; TxtFile IpFile = new TxtFile("deviceIp.txt"); IpFile.clearFile(); foreach (object o in kryptonComboBoxControllerIp.Items) { IpFile.writeFile(o.ToString()); } }