MSDN says:
An enumeration type (also named an enumeration or an enum) provides an efficient way to define a set of named integral constants that may be assigned to a variable.
You create a bit flags enum by applying the System.FlagsAttribute attribute and defining the values appropriately. That way you can use the bitwise operations like AND, OR and NOT on them.
In the following code example I've shown how to get Enum names and values, and how to use bitwise operations with enums.
1 using System;
2
3 namespace EnumTest
4 { 5 class Program
6 { 7 enum Days { Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, Sunday }; 8
9 [Flags] // Enables bitwise operations
10 public enum WaffleOptions
11 { 12 Cherries = 0x01,
13 IceCream = 0x02,
14 MapleSyrup = 0x04,
15 WhippedCream = 0x08,
16 Strawberries = 0x16
17 }
18
19
20 static void Main(string[] args)
21 { 22 int x = (int)Days.Monday;
23 int y = (int)Days.Friday;
24 Console.WriteLine("Monday = {0}", x); 25 Console.WriteLine("Friday = {0}", y); 26
27 // Output:
28 // Monday = 0
29 // Friday = 4
30
31 WaffleOptions waffleFillings = WaffleOptions.Cherries | WaffleOptions.WhippedCream;
32
33 Console.WriteLine("Waffle options are {0}", waffleFillings); 34
35 // Output:
36 // Waffle options are Cherries, WhippedCream
37
38 // gets the string value of Days-enum at index 4,
39 // which is Friday (Monday=0, .. Sunday=6)
40 string s = Enum.GetName(typeof(Days), 4);
41 Console.WriteLine(s);
42
43 // Output:
44 // Friday
45
46 // gets all the values of Days enum
47 Console.WriteLine("The values of the Days Enum are: "); 48 foreach (int i in Enum.GetValues(typeof(Days)))
49 Console.Write("{0} ", i); 50
51 // Output:
52 // 0 1 2 3 4 5 6 7
53
54 // gets all the names of Days enum
55 Console.WriteLine("\nThe names of the Days Enum are:"); 56 foreach (string str in Enum.GetNames(typeof(Days)))
57 Console.Write("{0} ", str); 58
59 Console.ReadLine();
60
61 }
62 }
63 }
1 using System;
2
3 namespace EnumParseTest
4 { 5 class Tester
6 { 7
8 // here's some enums. As you can see, we don't have to assign integer value to enum (Yellow)
9 enum Colors { Red = 1, Green = 2, Yellow }; 10
11 static void Main(string[] args)
12 { 13 Console.WriteLine();
14
15 // here's string values that are later parsed & checked if they are in Colors-enum
16 string[] colorStrings = { "Red", "Yellow", "Gray", "2", "12345"}; 17
18 foreach (string colorString in colorStrings)
19 { 20 try
21 { 22 Colors colorValue = (Colors)Enum.Parse(typeof(Colors), colorString);
23 // We need to check if parsed value is a member of Colors enum
24 // If we just parse the value, then value '12345' is assumed enum value.
25 if (Enum.IsDefined(typeof(Colors), colorValue) | colorValue.ToString().Contains(",")) 26 Console.WriteLine("Converted string '{0}' to Enum value {1}.", colorString, colorValue.ToString()); 27 else
28 Console.WriteLine("{0} is not a value of the Colors enumeration.", colorString); 29 }
30 catch (ArgumentException)
31 { 32 Console.WriteLine("'{0}' is not a member of the Colors enumeration.", colorString); 33 }
34 }
35
36 /*
37 Output:
38 Converted string 'Red' to Enum value Red.
39 Converted string 'Yellow' to Enum value Yellow.
40 'Gray' is not a member of the Colors enumeration.
41 Converted string '2' to Enum value Green.
42 12345 is not a value of the Colors enumeration.
43 */
44
45 Console.ReadLine();
46 }
47 }
48 }
Enums in MSDN:enum (C# Reference)Enumeration Types (C# Programming Guide)
