Question

I’m marking my enums with an own entity attribute used to map the enums to the corresponding field in a case management system.

Getting the correct string from an enum value works fine, but how can I generate an enum from a string?

I started by doing this:

foreach (var fieldInfo in enumType.GetFields())
{
    var attribute = (EntityNameAttribute)fieldInfo
        .GetCustomAttributes(typeof (EntityNameAttribute), false)
        .FirstOrDefault();

    if (attribute == null)
        continue;

    if (attribute.Name != name)
        continue;

    //got a match. But now what?
}

But how do I get the proper value from a field? Can I just use fieldInfo.GetValue? If so, what instance should I use? Should the enum be treated as a static type?

Answer 1

Yes, you can use:

object value = fieldInfo.GetValue(null);

They’re just static readonly fields, effectively. Note that that isn’t getting an enum from a string… but if you do need to do that, you can use Enum.Parse.

One thing to note – if you’re using .NET 3.5, your whole code can be simplified with LINQ:

var values = from field in enumType.GetFields()
             from EntityNameAttribute attribute in 
                   field.GetCustomAttributes((typeof(EntityNameAttribute), false)
             where attribute.Name == name
             select field.GetValue(null);

(That’s assuming that if there are multiple attributes of the right type defined, you don’t care which one has the right name, and only one will have the right name.)