Dynamic Linq OrderBy - Sort Field known only at Run-Time

A common issue with my LinqToSql stuff is the need to do an OrderBy on an IQueryable a la:

myQueryable = myQueryable.OrderBy(item => item.mySortField)

However, often you won't know the sort field until runtime, e.g. for a dynamically sortable grid.

One solution is to use the DynamicQueryable library provided by MS. It lets you do string-based dynamic querying like so:

myQueryable = myQueryable.OrderBy(mySortFieldName + " ASC"); // or use DESC if you like it in descending order

However this didn't have an option for using an IComparer to sort the results, and I wanted to use my NaturalSortComparer for natural case sorting. The solution I came up with was this:

myQueryable = myQueryable.OrderBy(item => item.GetReflectedPropertyValue(mySortFieldName ));

Or, actually employing NaturalSortComparer, like this:

myQueryable = myQueryable.OrderBy(item => item.GetReflectedPropertyValue(mySortFieldName ), new NaturalSortComparer<string>());

The solution uses a little helper method called GetReflectedPropertyValue():

        public static string GetReflectedPropertyValue(this object subject, string field)
        {
            object reflectedValue = subject.GetType().GetProperty(field).GetValue(subject, null);
            return reflectedValue != null ? reflectedValue.ToString() : "";
        }

OK, Reflection is slow (not sure how it compares to building a Lambda Expression tho) but it does the job for my purposes.