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Extending Enum to return attached string

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25 Oct 2012CPOL1 min read 12.6K   4   3
Extending Enum to return attached string

No of time there is requirement of getting string of Enum value to display purpose or to perform other task. So to deal with this requirement I wrote one extension function that get the string attached with the enum value.

Note : here attached string value is the attribute that is attached with each enum value that you are creating in enum variable.

Following is extension function to get string attached with enum.

public static class MyExtensions
{
   public static string GetEnumDescription(this Enum value)
   {            
         FieldInfo fi = value.GetType().GetField(value.ToString());
 
         object[] attributes = fi.GetCustomAttributes(true);
 
         if (attributes != null &&
            attributes.Length > 0)
                return ((DescriptionAttribute) attributes[0]).Description;
         else
                return value.ToString();
    }
}

The code above is making use of the reflection feature of .net framework. With the help of reflection it first get the information about the field and than get the attribute attached with that field. Attribute attached with enum value is DescriptionAttribute so code convert attribute object to DescriptionAttribute and return string attached with it. If there is no attribute attached with enum value it returns the interger value of enum as string.
 

Note : Attribute is metadata attached with the type you can attache metadata with class, function , property etc. Read More: Attributes (C# Programming Guide)
 

Following is simple program that is making use of extension function and to display the string attached with the enum value.

class Program
    {
        public enum WeekDay
        {
            [Description("Monday")]
            Monday,
            [Description("Tuesday")]
            Tuesday
        }
 
        static void Main(string[] args)
        {
            string str = (WeekDay.Monday).GetEnumDescription();
            Console.WriteLine(str);
            Console.ReadLine();
        }
    }

In above code there is enum create with the name WeekDay and as per the requirement it require to attache attribute with the each enum value to function to work properly if no attribute attached with enum value than function return value of enum i.e interger value associated with the enum.
 

So when code in "Main function" get executed call to function "GetEnumDescription" it return "Monday" as output on the console window which is associated with enum value.

License

This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)


Written By
Software Developer (Senior)
India India

Microsoft C# MVP (12-13)



Hey, I am Pranay Rana, working as a Team Leadin MNC. Web development in Asp.Net with C# and MS sql server are the experience tools that I have had for the past 5.5 years now.

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Comments and Discussions

 
GeneralMy vote of 2 Pin
Klaus Luedenscheidt26-Oct-12 17:31
Klaus Luedenscheidt26-Oct-12 17:31 
GeneralMy vote of 3 Pin
John Brett25-Oct-12 23:22
John Brett25-Oct-12 23:22 
Your extension method requests all of the custom attributes from the field, then makes the assumption that the first one it finds will be of type DescriptionAttribute. Needless to say, this will fail if your enum uses any other attributes.

It also doesn't address the question of internationalization. A common origin of this requirement is to be able to display a human-readable form of the enum - and that ought to be in the reader's own language.

So not the best implementation of this on CodeProject.
QuestionAnd a few more tips / articles like this on CP :) Pin
Vijay Gill25-Oct-12 22:30
professionalVijay Gill25-Oct-12 22:30 

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