Getting attributes of Enum's value

I would like to know if it is possible to get attributes of the enum values and not of the enum itself? For example, suppose I have the following enum:

using System.ComponentModel; // for DescriptionAttribute

enum FunkyAttributesEnum
{
    [Description("Name With Spaces1")]
    NameWithoutSpaces1,    
    [Description("Name With Spaces2")]
    NameWithoutSpaces2
}

What I want is given the enum type, produce 2-tuples of enum string value and its description.

Value was easy:

Array values = System.Enum.GetValues(typeof(FunkyAttributesEnum));
foreach (int value in values)
    Tuple.Value = Enum.GetName(typeof(FunkyAttributesEnum), value);

But how do I get description attribute's value, to populate Tuple.Desc? I can think of how to do it if the Attribute belongs to the enum itself, but I am at a loss as to how to get it from the value of the enum.

---

这应该做你需要的。

var type = typeof(FunkyAttributesEnum);
var memInfo = type.GetMember(FunkyAttributesEnum.NameWithoutSpaces1.ToString());
var attributes = memInfo[0].GetCustomAttributes(typeof(DescriptionAttribute), false);
var description = ((DescriptionAttribute)attributes[0]).Description;

---

This piece of code should give you a nice little extension method on any enum that lets you retrieve a generic attribute. I believe it's different to the lambda function above because it's simpler to use and slightly - you only need to pass in the generic type.

public static class EnumHelper
{
    /// <summary>
    /// Gets an attribute on an enum field value
    /// </summary>
    /// <typeparam name="T">The type of the attribute you want to retrieve</typeparam>
    /// <param name="enumVal">The enum value</param>
    /// <returns>The attribute of type T that exists on the enum value</returns>
    /// <example>string desc = myEnumVariable.GetAttributeOfType<DescriptionAttribute>().Description;</example>
    public static T GetAttributeOfType<T>(this Enum enumVal) where T:System.Attribute
    {
        var type = enumVal.GetType();
        var memInfo = type.GetMember(enumVal.ToString());
        var attributes = memInfo[0].GetCustomAttributes(typeof(T), false);
        return (attributes.Length > 0) ? (T)attributes[0] : null;
    }
}

---

This is a generic implementation using a lambda for the selection

public static Expected GetAttributeValue<T, Expected>(this Enum enumeration, Func<T, Expected> expression)
    where T : Attribute
{
    T attribute =
      enumeration
        .GetType()
        .GetMember(enumeration.ToString())
        .Where(member => member.MemberType == MemberTypes.Field)
        .FirstOrDefault()
        .GetCustomAttributes(typeof(T), false)
        .Cast<T>()
        .SingleOrDefault();

    if (attribute == null)
        return default(Expected);

    return expression(attribute);
}

Call it like this:

string description = targetLevel.GetAttributeValue<DescriptionAttribute, string>(x => x.Description);

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