How to localize an enum and use something similar to Html.SelectListFor<T>
Let's say that I got the following class and enum:
public class MyModel
{
[DisplayName("Min egenskap")]
public M开发者_Python百科yEnum TheProperty {get;set;}
}
public enum MyEnum
{
[DisplayName("Inga från Sverige")]
OneValue,
[DisplayName("Ett annat värde")]
AnotherValue
}
The above code doesn't work since DisplayNameAttribute
cannot be used on enums. Are there another attribute that can be used?
What I want to do is to generate a nice html select
tag using something like Html.SelectListFor(m => m.TheProperty)
. The list would use the DisplayNameAttribute
or similar attribute during generation.
Wanted result:
<select name="TheProperty">
<option value="OneValue">Inga från Sverige</option>
<option value="AnotherValue" selected="selected">Ett annat värde</option>
</select>
An example of how to do this is to use the [Description] attribute on your enum:
public enum DaysOfWeek
{
[Description("Monday")]
Monday = 1,
[Description("Tuesday")]
Tuesday = 2
}
Then create this EnumerationHelper class that will allow you to get the Description attribute of your enum:
public static class EnumerationHelper
{
//Transforms an enumeration description into a string
public static string Description<TEnum>(this TEnum enumObject)
{
Type type = enumObject.GetType();
MemberInfo[] memInfo = type.GetMember(enumObject.ToString());
if(memInfo != null && memInfo.Length > 0)
{
DescriptionAttribute[] attributes = (DescriptionAttribute[])memInfo[0].GetCustomAttributes(typeof(DescriptionAttribute), false);
if (attributes.Length > 0)
{
return attributes[0].Description;
}
}
return enumObject.ToString();
}
}
Then you can query your enum class to get the value and description to then build a SelectList. You must reference the EnumerationHelper in this class:
var listOfDaysOfWeek = (from DaysOfWeek d in Enum.GetValues(typeof(DaysOfWeek))
select new { ID = d, Description = d.Description() });
viewModel.selectListDaysOfWeek = new SelectList(listOfDaysOfWeek, "ID", "Description");
And then finally in your view:
<%: Html.DropDownListFor(m => m.DayOfWeek, Model.DaysOfWeek) %>
I hope this helps.
I wanted to display the Enum in the view so I made a similar Html helper:
/// <summary>
/// Returns the [Description] value of a Enum member.
/// </summary>
/// <typeparam name="TModel"></typeparam>
/// <typeparam name="TResult"></typeparam>
/// <param name="helper"></param>
/// <param name="expression"></param>
/// <returns></returns>
public static MvcHtmlString DisplayEnumFor<TModel, TResult>(this HtmlHelper<TModel> helper,
Expression<Func<TModel, TResult>> expression) where TResult : struct {
TResult value = expression.Compile().Invoke(helper.ViewData.Model);
string propName = ExpressionHelper.GetExpressionText(expression);
var description = typeof(TResult).GetMember(value.ToString())[0]
.GetCustomAttributes(typeof(DescriptionAttribute), true).FirstOrDefault();
if (description != null) {
return MvcHtmlString.Create((description as DescriptionAttribute).Description);
}
return MvcHtmlString.Create(value.ToString());
}
Usage:
@Html.DisplayEnumFor(m => m.SomeEnumProperty)
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