How to convert Enum to int by filling with zero on the left?

Question

Ladies and gentlemen, I have a question here of converting a enum in a string, but I need the conversion to be filled with zero to keep 2 digits.

Example

public enum System
{
    Unknown = 0,
    Mirror = 3,
    Order = 17
}

the Enum Mirror the out put would be "03".

tried with this example below worked

        int value;
        value = 3;
        Console.WriteLine(value.ToString("D2"));
        // Displays 03

But with Enum it doesn’t work.

Console.WriteLine(SourceSystem.Mirror.ToString("D2"));

The Following error appears:

System.FormatException 
Message=Format String can be only "G", "g", "X", "x", "F", "f", "D" or "d".....

Follows the enum:

    public enum SourceSystem
  {
    Unknown = 0,
    Mirror = 3,
    MirrorTrident = 17
  }

Answer 1

First you need to take the amount with a cast for example, and then turn into string, the pattern of ToString() of enum is to give the description of his name.

using static System.Console;

public class Program {
    public static void Main() {
        WriteLine(((int)SourceSystem.Mirror).ToString("D2"));
    }
}

public enum SourceSystem {
    Unknown = 0,
    Mirror = 3,
    MirrorTrident = 17
}

Behold working in the ideone. And in the .NET Fiddle. Also put on the Github for future reference.