private void AddButtonClick(object sender, EventArgs e) { string message; MacAddressMessageBox.TextColor = UIColor.DarkGray; if (!SignInManager.AddMacAddress(_fullName, _macAddress, out message)) { MacAddressMessageBox.TextColor = UIColor.Red; } else { _fullName = string.Empty; _macAddress = string.Empty; } _macAddressMessage = message; }