Convert String To Enum in a portable lib

Question

I'm trying to convert a string to an Enum, in a generic way, in a portable class Library

Targes are: .NET 4.5, Windows 8, Windows Phone 8.1, Windows Phone Silverlight 8

I have this string extension, which I've previous used in a Winform application. But in this library it does not compile. It is the line if (!typeof(TEnum).IsEnum) that doesn't work

public static class StringExtensions
{        

    public static TEnum? AsEnum<TEnum>(this string value) where TEnum : struct,  IComparable, IFormattable
    {
        if (!typeof(TEnum).IsEnum)
            throw new ArgumentException("TEnum must be an enumerated type");

        TEnum result;
        if (Enum.TryParse(value, true, out result))
            return result;

        return null;
    }
 }

So my question is: In the given context how do I test for a given type is an enum?

Can it be helpful? Like this: typeof(TEnum) is Enum. Source: http://stackoverflow.com/a/2918826/1380428 — Adil Mammadov, Jan 08 '15 at 12:45
Weird, the [documentation for `Type.IsEnum`](http://msdn.microsoft.com/en-us/library/system.type.isenum%28v=vs.110%29.aspx) specifies it as available in the portable library. — Jamiec, Jan 08 '15 at 12:46

score 3 · Answer 1 · answered Jan 08 '15 at 12:43

3

If Type.IsEnum isn't supported, you could always use:

if (typeof(TEnum).BaseType != typeof(Enum))

(Assuming BaseType is available, of course.)

answered Jan 08 '15 at 12:43

Jon Skeet

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Is `IsEnum` implemented this way? – Rico Suter Jan 08 '15 at 12:47
@RicoSuter: No idea. I suspect there's a more efficient way of doing it internally, but this should work. – Jon Skeet Jan 08 '15 at 12:51

score 2 · Accepted Answer · answered Jan 08 '15 at 12:49

2

You could try using GetTypeInfo:

using System.Reflection; // to get the extension method for GetTypeInfo()    

if(typeof(TEnum).GetTypeInfo().IsEnum)
  // whatever

answered Jan 08 '15 at 12:49

Jamiec

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Thank you for your helt I'd go with this solution because it was the closest to what I'd had allready. – Jens Borrisholt Jan 08 '15 at 12:57

Convert String To Enum in a portable lib

2 Answers2