How can I add option groups in ASP.NET drop down list?

Question

I have a requirement of grouping the drop down list options in ASP.NET drop down server control. Do you have any idea to how to approach the issue? I am new to ASP.NET.

Answer 1

I really like this client-side solution (doesn't need a custom DropDownList, but uses jQuery):

backend

private void _addSelectItem(DropDownList list, string title, string value, string group = null) {
   ListItem item = new ListItem(title, value);
   if (!String.IsNullOrEmpty(group))
   {
       item.Attributes["data-category"] = group;
   }
   list.Items.Add(item);
}

...
_addSelectItem(dropDown, "Option 1", "1");
_addSelectItem(dropDown, "Option 2", "2", "Category");
_addSelectItem(dropDown, "Option 3", "3", "Category");
...

client

var groups = {};
$("select option[data-category]").each(function () {
     groups[$.trim($(this).attr("data-category"))] = true;
});
$.each(groups, function (c) {
     $("select option[data-category='"+c+"']").wrapAll('');
});