CODEWITHSUNDEEP
c#enumstostring
Boris Callens
Boris Callens

Reputation: 93327

Enum ToString with user friendly strings

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.

Upvotes: 376

Views: 447360

Answers (27)

Al-Hanash Moataz
Al-Hanash Moataz

Reputation: 514

2023

public static string ToEnumString<T>(this T input) where T : Enum
{
     return Enum.GetName(typeof(T),input);
}

Usage:

public enum CommentInformType { Abuse, Misleading, Spam, BadMouth }
...
CommentInformType _informType = CommentInformType.Spam;
_informType.ToEnumString();

Upvotes: 1

Kiechlus
Kiechlus

Reputation: 1237

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("\"", "");
}

Upvotes: 4

Rodrigo
Rodrigo

Reputation: 198

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;

Upvotes: 2

A.B.
A.B.

Reputation: 2470

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")

Upvotes: 4

Emanuel Hiroshi
Emanuel Hiroshi

Reputation: 368

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

Upvotes: 2

zisha
zisha

Reputation: 11572

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));

Upvotes: -1

VladL
VladL

Reputation: 13033

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();

Upvotes: 0

J.M.H
J.M.H

Reputation: 85

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

Upvotes: 3

Brian Richardson
Brian Richardson

Reputation: 552

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");
}

Upvotes: 29

annakata
annakata

Reputation: 75794

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.

Upvotes: 102

samus
samus

Reputation: 6202

Some other more primitive options that avoid classes/reference types:

  • Array method
  • Nested struct method

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;
        }
    }
}

Upvotes: 12

Asher G.
Asher G.

Reputation: 5001

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.

Upvotes: 6

user1228
user1228

Reputation:

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!";
    }
  }
}

Upvotes: 439

Diogo Freitas
Diogo Freitas

Reputation: 69

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;
}

Upvotes: 6

user7096584
user7096584

Reputation: 1

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)
    {

    }

Upvotes: -2

Ray Booysen
Ray Booysen

Reputation: 30021

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();
}

Upvotes: 457

Lukich
Lukich

Reputation: 1

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);
    }

Upvotes: 0

Konrad Kokosa
Konrad Kokosa

Reputation: 16878

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)

Upvotes: 7

Milan Švec
Milan Švec

Reputation: 1813

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());

Upvotes: 8

StefanDK
StefanDK

Reputation: 173

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.

Upvotes: 3

underscore
underscore

Reputation: 772

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

Upvotes: 4

MarkusT
MarkusT

Reputation: 279

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)

Upvotes: 3

Richard Anthony Hein
Richard Anthony Hein

Reputation: 10650

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();
    }

Upvotes: 1

Joel MC
Joel MC

Reputation: 107

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();

Upvotes: 5

Noldorin
Noldorin

Reputation: 147290

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).

Upvotes: 21

Lemmy
Lemmy

Reputation: 3177

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.

Upvotes: 13

Kevin Pang
Kevin Pang

Reputation: 41442

If you want something completely customizable, try out my solution here:

http://www.kevinwilliampang.com/post/Mapping-Enums-To-Strings-and-Strings-to-Enums-in-NET.aspx

Basically, the post outlines how to attach Description attributes to each of your enums and provides a generic way to map from enum to description.

Upvotes: -4

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