Determine the name of a constant based on the value

Question

Is there a way of determining the name of a constant from a given value?

For example, given the following:

public const uint ERR_OK = 0x00000000;

How could one obtain "ERR_OK"?

I have been looking at refection but cant seem to find anything that helps me.

Answer 1

In general, you can't. There could be any number of constants with the same value. If you know the class which declared the constant, you could look for all public static fields and see if there are any with the value 0, but that's all. Then again, that might be good enough for you - is it? If so...

public string FindConstantName<T>(Type containingType, T value)
{
    EqualityComparer<T> comparer = EqualityComparer<T>.Default;

    foreach (FieldInfo field in containingType.GetFields
             (BindingFlags.Static | BindingFlags.Public))
    {
        if (field.FieldType == typeof(T) &&
            comparer.Equals(value, (T) field.GetValue(null)))
        {
            return field.Name; // There could be others, of course...
        }
    }
    return null; // Or throw an exception
}

Answer 2

I may be late.. but i think following could be the answer

public static class Names
    {
        public const string name1 = "Name 01";
        public const string name2 = "Name 02";

        public static string GetName(string code)
        {
            foreach (var field in typeof(Names).GetFields())
            {
                if ((string)field.GetValue(null) == code)
                    return field.Name.ToString();
            }
            return "";
        }
    }

and following will print "name1"

string result = Names.GetName("Name 01");
Console.WriteLine(result )

Answer 3

You may be interested in Enums instead, which can be programmatically converted from name to value and vice versa.