16 Jan 12 Razor DropDownList With Descriptions From An Enum Using Extentions, Generics, and Reflection.
A good test of a web framework is to see how it handles select boxes. It requires managing the list, the selected item across several states, be easily styled, be easily ajax-ed, and connect to a data store.
I like using Enums for static data, but they are a bit limited without a description value, you end up with select options labeled “ItemName ” instead of ”Human Friendly Item Name”.
Binding an enum to a dropdown is well documented. Adding descriptions to enums is also well documented. Here is a way to have enums with descriptions into a dropdown.
Your Enum
The Razor
This function will turn your enum into an IEnumerable<SelectListItem>
{
if (!typeof(T).IsEnum) throw new ArgumentException(“T must be an enumerated type”);
return Enum.GetValues(typeof(T))
.OfType<T>()
.Select(x => new SelectListItem()
{
Value = x.ToString(),
Text = (typeof(T)
.GetField(x.ToString())
.GetCustomAttributes(typeof(DescriptionAttribute), false)
.OfType<DescriptionAttribute>()
.FirstOrDefault() ?? new DescriptionAttribute(x.ToString())
).Description,
Selected = x.ToString() == (selectedvalue ?? “”)
});
}
Of course shortly after finishing this I found a great post on StackOverflow about making html helpers which results in an even prettier finish in razor, but requires a few extra helpers.
Minneapolis St. Paul IT expert, technical problem solver, tinkerer.
