My idea is to avoid magic string keys in my Asp.Net MVC application. To do so, I want to create string constant keys to be shared in the application.

For example, I can write TempData[MyClass.Message] or TempData[MyEnum.Message.ToString()] instead of TempData["Message"].

public class MyClass
{
    public const string Message = "Message";
}

and

public enum MyEnum
{
   Message,
   Others
}

My questions are: Which is the better way to avoid magic string keys? Using string const keys in a class or using enumeration together with ToString()?