My enum consists of the following values:
private enum PublishStatusses{ NotCompleted, Completed, Error }; I want to be able to output these values in a user friendly way though.
I don't need to be able to go from string to value again.
My enum consists of the following values:
private enum PublishStatusses{ NotCompleted, Completed, Error }; I want to be able to output these values in a user friendly way though.
I don't need to be able to go from string to value again.
I use the Description attribute from the System.ComponentModel namespace. Simply decorate the enum:
private enum PublishStatusValue { [Description("Not Completed")] NotCompleted, Completed, Error }; Then use this code to retrieve it:
public static string GetDescription<T>(this T enumerationValue) where T : struct { Type type = enumerationValue.GetType(); if (!type.IsEnum) { throw new ArgumentException("EnumerationValue must be of Enum type", "enumerationValue"); } //Tries to find a DescriptionAttribute for a potential friendly name //for the enum MemberInfo[] memberInfo = type.GetMember(enumerationValue.ToString()); if (memberInfo != null && memberInfo.Length > 0) { object[] attrs = memberInfo[0].GetCustomAttributes(typeof(DescriptionAttribute), false); if (attrs != null && attrs.Length > 0) { //Pull out the description value return ((DescriptionAttribute)attrs[0]).Description; } } //If we have no description attribute, just return the ToString of the enum return enumerationValue.ToString(); } ArgumentException, then there's no reason to have the method be completely generic.I do this with extension methods:
public enum ErrorLevel { None, Low, High, SoylentGreen } public static class ErrorLevelExtensions { public static string ToFriendlyString(this ErrorLevel me) { switch(me) { case ErrorLevel.None: return "Everything is OK"; case ErrorLevel.Low: return "SNAFU, if you know what I mean."; case ErrorLevel.High: return "Reaching TARFU levels"; case ErrorLevel.SoylentGreen: return "ITS PEOPLE!!!!"; default: return "Get your damn dirty hands off me you FILTHY APE!"; } } } default case implementation to return me.ToString() and only provide switch case statements for the enum values that you want to override. In your example, I get that they're all different but in actual use cases, I suspect that most of the single-word enum values will suffice and you'll only be providing overrides for multi-word enum values.Maybe I'm missing something, but what's wrong with Enum.GetName?
public string GetName(PublishStatusses value) { return Enum.GetName(typeof(PublishStatusses), value) } edit: for user-friendly strings, you need to go through a .resource to get internationalisation/localisation done, and it would arguably be better to use a fixed key based on the enum key than a decorator attribute on the same.
I created a reverse extension method to convert the description back into an enum value:
public static T ToEnumValue<T>(this string enumerationDescription) where T : struct { var type = typeof(T); if (!type.IsEnum) throw new ArgumentException("ToEnumValue<T>(): Must be of enum type", "T"); foreach (object val in System.Enum.GetValues(type)) if (val.GetDescription<T>() == enumerationDescription) return (T)val; throw new ArgumentException("ToEnumValue<T>(): Invalid description for enum " + type.Name, "enumerationDescription"); } The easiest solution here is to use a custom extension method (in .NET 3.5 at least - you can just convert it into a static helper method for earlier framework versions).
public static string ToCustomString(this PublishStatusses value) { switch(value) { // Return string depending on value. } return null; } I am assuming here that you want to return something other than the actual name of the enum value (which you can get by simply calling ToString).
That other post is Java. You can't put methods in Enums in C#.
just do something like this:
PublishStatusses status = ... String s = status.ToString(); If you want to use different display values for your enum values, you could use Attributes and Reflection.
Some other more primitive options that avoid classes/reference types:
Array method
private struct PublishStatusses { public static string[] Desc = { "Not Completed", "Completed", "Error" }; public enum Id { NotCompleted = 0, Completed, Error }; } Usage
string desc = PublishStatusses.Desc[(int)PublishStatusses.Id.Completed]; Nested struct method
private struct PublishStatusses { public struct NotCompleted { public const int Id = 0; public const string Desc = "Not Completed"; } public struct Completed { public const int Id = 1; public const string Desc = "Completed"; } public struct Error { public const int Id = 2; public const string Desc = "Error"; } } Usage
int id = PublishStatusses.NotCompleted.Id; string desc = PublishStatusses.NotCompleted.Desc; Update (03/09/2018)
A hybrid of Extension Methods and the first technique above.
I prefer enums to be defined where they "belong" (closest to their source of origin and not in some common, global namespace).
namespace ViewModels { public class RecordVM { //public enum Enum { Minutes, Hours } public struct Enum { public enum Id { Minutes, Hours } public static string[] Name = { "Minute(s)", "Hour(s)" }; } } } The extension method seems suited for a common area, and the "localized" definition of the enum now makes the extension method more verbose.
namespace Common { public static class EnumExtensions { public static string Name(this RecordVM.Enum.Id id) { return RecordVM.Enum.Name[(int)id]; } } } A usage example of the enum and it's extension method.
namespace Views { public class RecordView { private RecordDataFieldList<string, string> _fieldUnit; public RecordView() { _fieldUnit.List = new IdValueList<string, string> { new ListItem<string>((int)RecordVM.Enum.Id.Minutes, RecordVM.Enum.Id.Minutes.Name()), new ListItem<string>((int)RecordVM.Enum.Id.Hours, RecordVM.Enum.Id.Hours.Name()) }; } private void Update() { RecordVM.Enum.Id eId = DetermineUnit(); _fieldUnit.Input.Text = _fieldUnit.List.SetSelected((int)eId).Value; } } } Note: I actually decided to eliminate the Enum wrapper (and Name array), since it's best that the name strings come from a resource (ie config file or DB) instead of being hard-coded, and because I ended up putting the extension method in the ViewModels namespace (just in a different, "CommonVM.cs" file). Plus the whole .Id thing becomes distracting and cumbersome.
namespace ViewModels { public class RecordVM { public enum Enum { Minutes, Hours } //public struct Enum //{ // public enum Id { Minutes, Hours } // public static string[] Name = { "Minute(s)", "Hour(s)" }; //} } } CommonVM.cs
//namespace Common namespace ViewModels { public static class EnumExtensions { public static string Name(this RecordVM.Enum id) { //return RecordVM.Enum.Name[(int)id]; switch (id) { case RecordVM.Enum.Minutes: return "Minute(s)"; case RecordVM.Enum.Hours: return "Hour(s)"; default: return null; } } } } A usage example of the enum and it's extension method.
namespace Views { public class RecordView { private RecordDataFieldList<string, string> _fieldUnit public RecordView() { _fieldUnit.List = new IdValueList<string, string> { new ListItem<string>((int)RecordVM.Enum.Id.Minutes, RecordVM.Enum.Id.Minutes.Name()), new ListItem<string>((int)RecordVM.Enum.Id.Hours, RecordVM.Enum.Id.Hours.Name()) }; } private void Update() { RecordVM.Enum eId = DetermineUnit(); _fieldUnit.Input.Text = _fieldUnit.List.SetSelected((int)eId).Value; } } } The simplest way is just to include this extension class into your project, it will work with any enum in the project:
public static class EnumExtensions { public static string ToFriendlyString(this Enum code) { return Enum.GetName(code.GetType(), code); } } Usage:
enum ExampleEnum { Demo = 0, Test = 1, Live = 2 } ...
ExampleEnum ee = ExampleEnum.Live; Console.WriteLine(ee.ToFriendlyString()); string result = "Result: " + ee;You can use Humanizer package with Humanize Enums possiblity. An eaxample:
enum PublishStatusses { [Description("Custom description")] NotCompleted, AlmostCompleted, Error }; then you can use Humanize extension method on enum directly:
var st1 = PublishStatusses.NotCompleted; var str1 = st1.Humanize(); // will result in Custom description var st2 = PublishStatusses.AlmostCompleted; var str2 = st2.Humanize(); // will result in Almost completed (calculated automaticaly) public enum MyEnum { [Description("Option One")] Option_One } public static string ToDescriptionString(this Enum This) { Type type = This.GetType(); string name = Enum.GetName(type, This); MemberInfo member = type.GetMembers() .Where(w => w.Name == name) .FirstOrDefault(); DescriptionAttribute attribute = member != null ? member.GetCustomAttributes(true) .Where(w => w.GetType() == typeof(DescriptionAttribute)) .FirstOrDefault() as DescriptionAttribute : null; return attribute != null ? attribute.Description : name; } this parameter in extension methods, that you can see called This in many examples in the web. Calling it like its type like you did (Enum Enum) make the code less readable.Instead of using an enum use a static class.
replace
private enum PublishStatuses{ NotCompleted, Completed, Error }; with
private static class PublishStatuses{ public static readonly string NotCompleted = "Not Completed"; public static readonly string Completed = "Completed"; public static readonly string Error = "Error"; }; it will be used like this
PublishStatuses.NotCompleted; // "Not Completed" Issue using the top "extension method" solutions:
A private enum is often used inside another class. The extension method solution is not valid there since it must be in it's own class. This solution can be private and embedded in another class.
Enums when passing to methods as all methods signatures will require string so anything could be passed; introducing the need for additional validation and decreasing general readability.With respect to Ray Booysen, there is a bug in the code: Enum ToString with user friendly strings
You need to account for multiple attributes on the enum values.
public static string GetDescription<T>(this object enumerationValue) where T : struct { Type type = enumerationValue.GetType(); if (!type.IsEnum) { throw new ArgumentException("EnumerationValue must be of Enum type", "enumerationValue"); } //Tries to find a DescriptionAttribute for a potential friendly name //for the enum MemberInfo[] memberInfo = type.GetMember(enumerationValue.ToString()); if (memberInfo != null && memberInfo.Length > 0) { object[] attrs = memberInfo[0].GetCustomAttributes(typeof(DescriptionAttribute), false); if (attrs != null && attrs.Length > 0 && attrs.Where(t => t.GetType() == typeof(DescriptionAttribute)).FirstOrDefault() != null) { //Pull out the description value return ((DescriptionAttribute)attrs.Where(t=>t.GetType() == typeof(DescriptionAttribute)).FirstOrDefault()).Description; } } //If we have no description attribute, just return the ToString of the enum return enumerationValue.ToString(); Clean summary of the above suggestions with sample:
namespace EnumExtensions { using System; using System.Reflection; public class TextAttribute : Attribute { public string Text; public TextAttribute( string text ) { Text = text; }//ctor }// class TextAttribute public static class EnumExtender { public static string ToText( this Enum enumeration ) { MemberInfo[] memberInfo = enumeration.GetType().GetMember( enumeration.ToString() ); if ( memberInfo != null && memberInfo.Length > 0 ) { object[] attributes = memberInfo[ 0 ].GetCustomAttributes( typeof(TextAttribute), false ); if ( attributes != null && attributes.Length > 0 ) { return ( (TextAttribute)attributes[ 0 ] ).Text; } }//if return enumeration.ToString(); }//ToText }//class EnumExtender }//namespace USAGE:
using System; using EnumExtensions; class Program { public enum Appearance { [Text( "left-handed" ) ] Left, [Text( "right-handed" ) ] Right, }//enum static void Main( string[] args ) { var appearance = Appearance.Left; Console.WriteLine( appearance.ToText() ); }//Main }//class I'm 7 years late for the party :-) But I'm sure this topic is visited frequently.
So I wanted to add a little sugar to the coffee:
What about the "F" format string specifier?
PublishStatusses[] ps = Enum.GetValues<PublishStatusses>(); ps.ToList().ForEach(c => Console.Write($"{c:F} ")); There is no need for any explicit function call.
In fact there isn't even need for any format specifier. In case of a variable assignment to a string, ToString() does the work:
string foo = PublishStatusses.Error.ToString(); // or ToString("F") And if it is about to insert spaces between words of a CamelCase string, you can just use a regular expression:
Regex.Replace(foo, "(\\B[A-Z])", " $1") I happen to be a VB.NET fan, so here's my version, combining the DescriptionAttribute method with an extension method. First, the results:
Imports System.ComponentModel ' For <Description> Module Module1 ''' <summary> ''' An Enum type with three values and descriptions ''' </summary> Public Enum EnumType <Description("One")> V1 = 1 ' This one has no description V2 = 2 <Description("Three")> V3 = 3 End Enum Sub Main() ' Description method is an extension in EnumExtensions For Each v As EnumType In [Enum].GetValues(GetType(EnumType)) Console.WriteLine("Enum {0} has value {1} and description {2}", v, CInt(v), v.Description ) Next ' Output: ' Enum V1 has value 1 and description One ' Enum V2 has value 2 and description V2 ' Enum V3 has value 3 and description Three End Sub End Module Basic stuff: an enum called EnumType with three values V1, V2 and V3. The "magic" happens in the Console.WriteLine call in Sub Main(), where the last argument is simply v.Description. This returns "One" for V1, "V2" for V2, and "Three" for V3. This Description-method is in fact an extension method, defined in another module called EnumExtensions:
Option Strict On Option Explicit On Option Infer Off Imports System.Runtime.CompilerServices Imports System.Reflection Imports System.ComponentModel Module EnumExtensions Private _Descriptions As New Dictionary(Of String, String) ''' <summary> ''' This extension method adds a Description method ''' to all enum members. The result of the method is the ''' value of the Description attribute if present, else ''' the normal ToString() representation of the enum value. ''' </summary> <Extension> Public Function Description(e As [Enum]) As String ' Get the type of the enum Dim enumType As Type = e.GetType() ' Get the name of the enum value Dim name As String = e.ToString() ' Construct a full name for this enum value Dim fullName As String = enumType.FullName + "." + name ' See if we have looked it up earlier Dim enumDescription As String = Nothing If _Descriptions.TryGetValue(fullName, enumDescription) Then ' Yes we have - return previous value Return enumDescription End If ' Find the value of the Description attribute on this enum value Dim members As MemberInfo() = enumType.GetMember(name) If members IsNot Nothing AndAlso members.Length > 0 Then Dim descriptions() As Object = members(0).GetCustomAttributes(GetType(DescriptionAttribute), False) If descriptions IsNot Nothing AndAlso descriptions.Length > 0 Then ' Set name to description found name = DirectCast(descriptions(0), DescriptionAttribute).Description End If End If ' Save the name in the dictionary: _Descriptions.Add(fullName, name) ' Return the name Return name End Function End Module Because looking up description attributes using Reflection is slow, the lookups are also cached in a private Dictionary, that is populated on demand.
(Sorry for the VB.NET solution - it should be relatively straighforward to translate it to C#, and my C# is rusty on new subjects like extensions)
ToString(string) in modern versions of .net already avoids boxing and caches results, so the manual implementation is unnecessary, these days, and likely less performant than the built-in methods.Even cleaner summary:
using System; using System.Reflection; public class TextAttribute : Attribute { public string Text; public TextAttribute(string text) { Text = text; } } public static class EnumExtender { public static string ToText(this Enum enumeration) { var memberInfo = enumeration.GetType().GetMember(enumeration.ToString()); if (memberInfo.Length <= 0) return enumeration.ToString(); var attributes = memberInfo[0].GetCustomAttributes(typeof(TextAttribute), false); return attributes.Length > 0 ? ((TextAttribute)attributes[0]).Text : enumeration.ToString(); } } Same usage as underscore describes.
Use Enum.GetName
From the above link...
using System; public class GetNameTest { enum Colors { Red, Green, Blue, Yellow }; enum Styles { Plaid, Striped, Tartan, Corduroy }; public static void Main() { Console.WriteLine("The 4th value of the Colors Enum is {0}", Enum.GetName(typeof(Colors), 3)); Console.WriteLine("The 4th value of the Styles Enum is {0}", Enum.GetName(typeof(Styles), 3)); } } // The example displays the following output: // The 4th value of the Colors Enum is Yellow // The 4th value of the Styles Enum is Corduroy ToString(string) method is in all .net versions back to framework 1.1 and standard 1.0, so it is there and won't throw on a missing value.In case you use Newtonsoft anyway, you can do it as follows:
// Enum [Newtonsoft.Json.JsonConverter(typeof(StringEnumConverter))] public enum MyEnum { [EnumMember(Value = "User friendly value")] SomeValue=0, } // Usage as extension method public static string ToDefaultString(this Enum enumValue) { return JsonConvert.SerializeObject(enumValue).Replace("\"", ""); } According to this documentation: https://learn.microsoft.com/pt-br/dotnet/api/system.enum.tostring?view=netframework-4.8
It is possible to just convert a enumerator to string using a format like this:
public enum Example { Example1, Example2 } Console.WriteLine(Example.Example1.ToString("g")); //Outputs: "Example1" You can see all the possible formats in this link: https://learn.microsoft.com/pt-br/dotnet/api/system.string?view=netframework-4.8
ToString(IFormatProvider) method. The most efficient method tends to be an extension method with a switch expression returning strings based on the enum value and whatever other behaviors you may want to add on top of that.Just use a static class that simulate an enum:
public static class PublishStatusses{ public const string NotCompleted = "Not Completed"; public const string Completed = "Completed"; public const string Error = "Error" }; And to access the values, just use like an enum:
PublishStatusses.NotCompleted; This is an update to Ray Booysen's code that uses the generic GetCustomAttributes method and LINQ to make things a bit tidier.
/// <summary> /// Gets the value of the <see cref="T:System.ComponentModel.DescriptionAttribute"/> on an struct, including enums. /// </summary> /// <typeparam name="T">The type of the struct.</typeparam> /// <param name="enumerationValue">A value of type <see cref="T:System.Enum"/></param> /// <returns>If the struct has a Description attribute, this method returns the description. Otherwise it just calls ToString() on the struct.</returns> /// <remarks>Based on http://stackoverflow.com/questions/479410/enum-tostring/479417#479417, but useful for any struct.</remarks> public static string GetDescription<T>(this T enumerationValue) where T : struct { return enumerationValue.GetType().GetMember(enumerationValue.ToString()) .SelectMany(mi => mi.GetCustomAttributes<DescriptionAttribute>(false), (mi, ca) => ca.Description) .FirstOrDefault() ?? enumerationValue.ToString(); } For flags enum including.
public static string Description(this Enum value) { Type type = value.GetType(); List<string> res = new List<string>(); var arrValue = value.ToString().Split(',').Select(v=>v.Trim()); foreach (string strValue in arrValue) { MemberInfo[] memberInfo = type.GetMember(strValue); if (memberInfo != null && memberInfo.Length > 0) { object[] attrs = memberInfo[0].GetCustomAttributes(typeof(DescriptionAttribute), false); if (attrs != null && attrs.Length > 0 && attrs.Where(t => t.GetType() == typeof(DescriptionAttribute)).FirstOrDefault() != null) { res.Add(((DescriptionAttribute)attrs.Where(t => t.GetType() == typeof(DescriptionAttribute)).FirstOrDefault()).Description); } else res.Add(strValue); } else res.Add(strValue); } return res.Aggregate((s,v)=>s+", "+v); } In case you just want to add a whitespace between the words, it is as simple as
string res = Regex.Replace(PublishStatusses.NotCompleted, "[A-Z]", " $0").Trim(); default clause of the switch statement/expression, but I still wouldn't.I use a generic class to store the enum/description pairs and a nested helper class to get the description.
The enum:
enum Status { Success, Fail, Pending } The generic class:
Note: Since a generic class cannot be constrained by an enum I am constraining by struct instead and checking for enum in the constructor.
public class EnumX<T> where T : struct { public T Code { get; set; } public string Description { get; set; } public EnumX(T code, string desc) { if (!typeof(T).IsEnum) throw new NotImplementedException(); Code = code; Description = desc; } public class Helper { private List<EnumX<T>> codes; public Helper(List<EnumX<T>> codes) { this.codes = codes; } public string GetDescription(T code) { EnumX<T> e = codes.Where(c => c.Code.Equals(code)).FirstOrDefault(); return e is null ? "Undefined" : e.Description; } } } Usage:
EnumX<Status>.Helper StatusCodes = new EnumX<Status>.Helper(new List<EnumX<Status>>() { new EnumX<Status>(Status.Success,"Operation was successful"), new EnumX<Status>(Status.Fail,"Operation failed"), new EnumX<Status>(Status.Pending,"Operation not complete. Please wait...") }); Console.WriteLine(StatusCodes.GetDescription(Status.Pending)); I think the best (and easiest) way to solve your problem is to write an Extension-Method for your enum:
public static string GetUserFriendlyString(this PublishStatusses status) { }