Supporting Enum in EF 5 with .Net 4.0

Question

I'm currently working through Getting Started with EF5 using MVC 4 in Visual Studio 2010 (.NET 4.0) to learn about how to use ASP.NET and Entity Framework. During the beginning of the tutorial I ran into an issue with enum support when creating a database with Code First Migrations. For reasons unknown I have to work in this environment and create my own support for enums so I decided to make the property int instead then I would convert it to Enum when I want to display it like so:

using System;
using System.Web;
using System.Web.Mvc;
using System.Web.Mvc.Html;
using System.Linq;
using System.Linq.Expressions;
namespace ContosoUniversity.Extensions
{
 public static class Extensions
 {
 public static String DisplayAsEnum<TModel, TValue>(this HtmlHelper<TModel> cHtml,
 Expression<Func<TModel, TValue>> cExpression,
 Type cType,
 String strDisplay = "Unknown")
 {
 try
 {
 if (cType.IsEnum)
 {
 object cResult = cExpression.Compile().DynamicInvoke(cHtml.ViewData.Model);
 if (cResult != null)
 {
 strDisplay = Enum.ToObject(cType, cResult).ToString();
 }
 }
 }
 catch (Exception cExc)
 {
 strDisplay = cExc.ToString();
 }
 return (strDisplay);
 }
 }
}

In my razor cshtml file I display it to the webpage with this call:

@Html.DisplayAsEnum(modelItem => item.Grade, typeof(Grade), "No Grade")

I have a feeling that this is not the "professional" or "right" way of handling the lack of enum support so I was wondering if there is anyway to improve this function or is there a better way of handling enumerations in EF 5 with .Net 4.0 support?

I was shown a Stack Overflow question that provides me with a better solution to handling the enum support. It is very helpful and I am using it at the moment, but since I do like the function that I made, is it possible to improve it?

• Greg Burghardt: This StackOverflow question should be right up your alley. In my opinion the accepted answer is a cleaner solution.
• John Odom: @GregBurghardt It looks like I should of paid more attention to StackOverflow before posting my question lol. That did work for me, and without needed to re-update the database. Thanks!

Answer 1

Ideally you won't want to change the strDisplay, so we should probably take it out of the parameter list and make it a constant inside the method and then just return in each of the 3 circumstances.

var display = "Unknown";
try
{
 if (cType.IsEnum)
 {
 object cResult = cExpression.Compile().DynamicInvoke(cHtml.ViewData.Model);
 if (cResult != null)
 {
 return Enum.ToObject(cType, cResult).ToString();
 }
 }
}
catch (Exception cExc)
{
 return cExc.ToString();
}
return display;

this seems weird to me that we are using the variable (whatever you choose to name it) only once, I would probably in this circumstance (since we aren't allowing it to be changed) just return the string Unknown like this

try
{
 if (cType.IsEnum)
 {
 object cResult = cExpression.Compile().DynamicInvoke(cHtml.ViewData.Model);
 if (cResult != null)
 {
 return Enum.ToObject(cType, cResult).ToString();
 }
 }
}
catch (Exception cExc)
{
 return cExc.ToString();
}
return "Unknown";

• John Odom: I don't know why the other answer got deleted but I do like this answer. It does make sense to me to not change strDisplay. I don't know what I was thinking at the time lol. Thanks for the answer!