Why does Enum.Parse create undefined entries?

Question

class Program
{
    static void Main(string[] args)
    {
        string value = "12345";
        Type enumType = typeof(Fruits);
        Fruits fruit = Fr         


        

Answer 1

You need to use Enum.IsDefined:

http://msdn.microsoft.com/en-us/library/essfb559.aspx

using System;

    [Flags] enum Colors { None=0, Red = 1, Green = 2, Blue = 4 };

    public class Example
    {
       public static void Main()
       {
          string[] colorStrings = { "0", "2", "8", "blue", "Blue", "Yellow", "Red, Green" };
          foreach (string colorString in colorStrings)
          {
             try {
                Colors colorValue = (Colors) Enum.Parse(typeof(Colors), colorString);        
                if (Enum.IsDefined(typeof(Colors), colorValue) | colorValue.ToString().Contains(","))  
                   Console.WriteLine("Converted '{0}' to {1}.", colorString, colorValue.ToString());
                else
                   Console.WriteLine("{0} is not an underlying value of the Colors enumeration.", colorString);
             }
             catch (ArgumentException) {
                Console.WriteLine("'{0}' is not a member of the Colors enumeration.", colorString);
             }
          }
       }
    }
    // The example displays the following output:
    //       Converted '0' to None.
    //       Converted '2' to Green.
    //       8 is not an underlying value of the Colors enumeration.
    //       'blue' is not a member of the Colors enumeration.
    //       Converted 'Blue' to Blue.
    //       'Yellow' is not a member of the Colors enumeration.
    //       Converted 'Red, Green' to Red, Green.