Casting en enum to its underlying type.

First of all, I managed to figure it out. You can use Type.UnderlyingSystemType to get the underlying type of the enum, and then use the System.Convert class to convert the enum to its underlying type. The reason it matters is because I need to write an Enum to a memory stream, but memory space is very important and thus I wanted it to take up as little space as possible.

Quick question, not that I think you're wrong, but why is the underlying type important?

I don't think you understand my question... I know how to case a enum Foo : int {...} to an int. That's easy. Here's an example of what I want... enum Foo1 : byte { A=5, B=10, } enum Foo2 : long { One=1, Two=2, } static void Main() { Foo1 f1 = Foo1.A; Foo2 f2 = Foo2.One; object o1 = Bar(f1); object o2 = Bar(f2); Console.WriteLine(o1); Console.WriteLine(o1.GetType().Name); Console.WriteLine(o2); Console.WriteLine(o2.GetType().Name); } static object Bar(Enum e) { return e.ToUnderlyingType(); // I made this method up. I need something equivalent. } Which would output: 5 Byte 1 Int64 Thanks.

To add to that, you can also cast to an enumeration from an int. (Colors)2 is the same as Colors.Blue.

If I remember correctly, instances of enumerations can be cast to integers to get their underlying values, for example: enum Colors{Red = 1, Blue = 2, Green = 4} Console.WriteLine( ((int)(Colors.Red)).ToString() ) writes 1 to the console. int e = (int)(Colors.Green && Colors.Blue); Console.WriteLine( e.ToString() ); writes 6 to the console. int a = (int)Colors.Green; int b = (int)Colors.Red; Console.WriteLine ( (a+b).ToString() ); writes 3 to the console.

Sorry, didn't read your question to the end... :-))

Hi What do you mean by "underlying" type? Color c = Color.Green; byte b = (byte) c; // b == 1 public enum Color : byte { Red, Green, Blue } or... That all enum's are derived from System.Enum and System.Enum is derived from System.ValueType ... ?? Simon