从描述属性获取枚举

问题描述

我有一个通用扩展方法，从枚举中获取描述属性：

I have a generic extension method which gets the Description attribute from an Enum:

enum Animal
{
    [Description("")]
    NotSet = 0,

    [Description("Giant Panda")]
    GiantPanda = 1,

    [Description("Lesser Spotted Anteater")]
    LesserSpottedAnteater = 2
}

public static string GetDescription(this Enum value)
{
    FieldInfo field = value.GetType().GetField(value.ToString());

    DescriptionAttribute attribute
            = Attribute.GetCustomAttribute(field, typeof(DescriptionAttribute))
                as DescriptionAttribute;

    return attribute == null ? value.ToString() : attribute.Description;
}

所以我可以做...

string myAnimal = Animal.GiantPanda.GetDescription(); // = "Giant Panda"

现在，我试图找出相应的功能其他方向，如...

now, I'm trying to work out the equivalent function in the other direction, something like...

Animal a = (Animal)Enum.GetValueFromDescription("Giant Panda", typeof(Animal));

推荐答案

public static class EnumEx
{
    public static T GetValueFromDescription<T>(string description)
    {
        var type = typeof(T);
        if(!type.IsEnum) throw new InvalidOperationException();
        foreach(var field in type.GetFields())
        {
            var attribute = Attribute.GetCustomAttribute(field,
                typeof(DescriptionAttribute)) as DescriptionAttribute;
            if(attribute != null)
            {
                if(attribute.Description == description)
                    return (T)field.GetValue(null);
            }
            else
            {
                if(field.Name == description)
                    return (T)field.GetValue(null);
            }
        }
        throw new ArgumentException("Not found.", "description");
        // or return default(T);
    }
}

用法：

var panda = EnumEx.GetValueFromDescription<Animal>("Giant Panda");

这篇关于从描述属性获取枚举的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！