I ended up doing creating a html helper method that takes my two list, and for each item creates a new Tag of "option" type, and add it to a select list. That way I can add attributes, such as "disabled="disabled"" and so on.
It's not neat, it's not tidy. To be honest, it's kind of aweful code, and I would love to have a better way to do it. However, at the moment short of time to complete my task, so ended up doing this way:
var fullList = new StringBuilder();
var selectList = new TagBuilder("select");
selectList.Attributes.Add("name", "currencies");
selectList.Attributes.Add("id", "selectCurrency");
foreach (var currency in currencies)
{
var option = new TagBuilder("option") {InnerHtml = currency.Id};
option.Attributes.Add("value", currency.Id);
fullList.AppendLine(option.ToString());
}
var separator = new TagBuilder("option") { InnerHtml = "-------" };
separator.Attributes.Add("disabled", "disabled");
fullList.AppendLine(separator.ToString());
selectList.InnerHtml = fullList.ToString();
If you have a better way, please let me know, and I'll might be able to revisit this task later on for some refactoring, and would love to have a good way to do it then.