Generic Method to get string from ENUM (by passing int Value)

Question

i have written a generic method to convert int to Enum String, getting an error. Please Help Thanx.

    public static string GetStringEquiValentOFEnumFromString<T>(int enumVal)
        where T : struct
    {
        if(Enum.IsDefined(typeof(T),enumVal))
        {
            return ((T)enumVal).ToString();  ///Error: Cannot convert type 'int' to 'T'
        }          
        return null;  
    }

I'm pretty sure that this won't handle combined values of flags enums. — phoog, Feb 16 '12 at 22:00

score 2 · Answer 1 · answered Feb 16 '12 at 21:47

2

I think you can use Enum.ToObject:

public static string GetStringEquiValentOFEnumFromString<T>(int enumVal)
     where T : struct
    {
        if (Enum.IsDefined(typeof(T), enumVal))
        {
            return Enum.ToObject(typeof (T), enumVal).ToString();
        }
    }

http://msdn.microsoft.com/en-us/library/system.enum.toobject.aspx

answered Feb 16 '12 at 21:47

DMac the Destroyer

5,240
6
36
56

forgot to give props: pulled it from this SO answer: http://stackoverflow.com/a/29485/437456 – DMac the Destroyer Feb 16 '12 at 21:48

score 0 · Answer 2 · answered Jun 13 '13 at 16:35

public static class StringEnum {

    public static string GetStringValue(Enum value)
    {
        string output = null;
        Type type = value.GetType();

        FieldInfo fi = type.GetField(value.ToString());
        StringValue[] attr = fi.GetCustomAttributes(typeof(StringValue), false) as StringValue[];

        if (attr.Length > 0)
        {
            output = attr[0].Value;
        }
        return output;
    }
}

StringEnum is a class which have (GetStringValue) method to get the string value.

public enum CampaignRequestType { [StringValue("None")] None = 0, [StringValue("Pharmacy Cards")] Pharmacy_Cards = 1,[StringValue("Prospect Campaign")] Prospect_Campaign = 2,[StringValue("Tradeshow/Advertising")] Tradeshow_Advertising = 3 }

its a enum...

string item = StringEnum.GetStringValue((Enumeration.CampaignRequestType)updateRequestStatus.RequestType_Code);

here (Enumeration.CampaignRequestType) is my enumeration and updateRequestStatus.RequestType_Code is data base field int type

i cast int value to enumeration type

Ron Warholic · Answer 3 · 2012-02-16T23:16:02.090

You're seeing this error because generic type arguments cannot be constrained to the enum type in C#. Since your constraint only says it has to be a value type the compiler cannot guarantee that enumVal will be convertible to T and gives a compile time error.

To get around this you can explicitly define the enum type in the function:

public static string GetStringFromValue(this MyEnum enum, int val) {
   if (Enum.IsDefined(typeof(MyEnum), val)) {
      return ((MyEnum) val).ToString();
   }
   return null;
}

Or you can use something like Jon Skeet's UnconstrainedMelody library which rewrites your code at the bytecode level to enforce the enum constraint (callable from another assembly).

there's another wrinkle, which is that the enum might have a smaller type than `int` as its underlying type. — phoog, Feb 16 '12 at 21:58

score 0 · Answer 4 · answered Feb 16 '12 at 22:00

This ought to work:

public static string GetStringEquiValentOFEnumFromString<T>(int enumVal) 
    where T : struct 
{ 
    if(Enum.IsDefined(typeof(T),enumVal)) 
    { 
        return ((T)(object)enumVal).ToString();
    }           
    return null;   
}

Generic Method to get string from ENUM (by passing int Value)

4 Answers4