Parse string to enum type

Question

I have an enum type like this as an example:

public Enum MyEnum {
    enum1, enum2, enum3 };

I'll read a string from config file. What I need is to parse the string to MyEnum type or null or not defined. Not sure if the following code will work (sorry for not having access to my VS right now):

// example: ParseEnum<MyEnum>("ENUM1", ref eVal);
bool ParseEnum<T>(string value1, ref eVal) where T : Enum
{
  bool bRet = false;
  var x = from x in Enum.GetNames(typeof(T)) where 
       string.Equals(value1, x, StringComparison. OrdinalIgnoreCase)
       select x;
  if (x.Count() == 1 )
  {
    eVal = Enum.Parse(typeof(T), x.Item(0)) as T;
    bRet = true;
  }
  return bRet;
}

Not sure if it is correct or there is any other simple way to parse a string to a MyEnum value?

Answer 1

What about something like:

public static class EnumUtils
{
    public static Nullable<T> Parse<T>(string input) where T : struct
    {
        //since we cant do a generic type constraint
        if (!typeof(T).IsEnum)
        {
            throw new ArgumentException("Generic Type 'T' must be an Enum");
        }
        if (!string.IsNullOrEmpty(input))
        {
            if (Enum.GetNames(typeof(T)).Any(
                  e => e.Trim().ToUpperInvariant() == input.Trim().ToUpperInvariant()))
            {
                return (T)Enum.Parse(typeof(T), input, true);
            }
        }
        return null;
    }
}

Used as:

MyEnum? value = EnumUtils.Parse<MyEnum>("foo");

(Note: old version used try/catch around Enum.Parse)

Answer 2

private enum MyEnum
{
    Enum1 = 1, Enum2 = 2, Enum3 = 3, Enum4 = 4, Enum5 = 5, Enum6 = 6, 
    Enum7 = 7, Enum8 = 8, Enum9 = 9, Enum10 = 10
}

private static Object ParseEnum<T>(string s)
{
    try
    {
        var o = Enum.Parse(typeof (T), s);
        return (T)o;
    }
    catch(ArgumentException)
    {
        return null;
    }
}

static void Main(string[] args)
{
   Console.WriteLine(ParseEnum<MyEnum>("Enum11"));
   Console.WriteLine(ParseEnum<MyEnum>("Enum1"));
   Console.WriteLine(ParseEnum<MyEnum>("Enum6").GetType());
   Console.WriteLine(ParseEnum<MyEnum>("Enum10"));
}

OUTPUT:

    //This line is empty as Enum11 is not there and function returns a null
Enum1
TestApp.Program+MyEnum
Enum10
Press any key to continue . . .