Using C# Enum Flags To Return A Set Of Values Based On Their Bit-Wise OR'ed Values

Question

I understand that you can configure C# enum flags in this way:

    [Flags]
    public enum MyEnum
    {
        Unknown = 0,
        Type1 = 1,
        Type2 = 2,
        Type3 = 4,
        Type4 = 8,
        Type5 = 16
    }

And once this is configured, you can represent a set of enumberations like so:

MyEnum enumerationSet = MyEnum.Type1 | MyEnum.Type2

Then you can make checks against this set, such as:

if(enumerationSet.HasFlag(MyEnum.Type1))
{
  // Do something
}

Or print their values, like so:

Console.WriteLine("{0}", enumerationSet);

Which would print:

Type1, Type2

However, can I go in reverse order? For instance, if I know that

MyEnum.Type1 | MyEnum.Type2 == 3

Can I then ask MyEnum what set of its value/types would equal 3? Then, I can create an extension method (GetSet) to execute like this:

List<MyEnum> myEnumSetList = MyEnum.GetSet(3)

Returning either a MyEnum set or a set of values, i.e. {1, 2}.

Please advise.

---

EDIT: I was able to finally figure it out. Posted my answer below.

Answer 1

After some hacking around, I was able to resolve a list of enum values, based on the value of that respective set OR'ed:

protected List<MyEnum> GetEnumSet(int flagNumber)
{
      List<MyEnum> resultList= new List<MyEnum>();

      foreach (MyEnum value in Enum.GetValues(typeof(MyEnum)))
      {
         if (((MyEnum)flagNumber).HasFlag(value))
         {
             resultList.Add(value);
         }
      }

      return resultList;
}

Here, flagNumber is the value of a respective list OR'ed, i.e. MyEnum.Type1 | MyEnum.Type2. Thus, by sending this method the flagNumber, I get the list { MyEnum.Type1, MyEnum.Type2 }