Freely convert between List and IEnumerable

Question

How can I convert a List to an IEnumerable and then back again?

I want to do this in order to run a series

Answer 1

Aside: Note that the standard LINQ operators (as per the earlier example) don't change the existing list - list.OrderBy(...).ToList() will create a new list based on the re-ordered sequence. It is pretty easy, however, to create an extension method that allows you to use lambdas with List.Sort:

static void Sort(this List list,
    Func selector)
{
    var comparer = Comparer.Default;
    list.Sort((x,y) => comparer.Compare(selector(x), selector(y)));
}

static void SortDescending(this List list,
    Func selector)
{
    var comparer = Comparer.Default;
    list.Sort((x,y) => comparer.Compare(selector(y), selector(x)));
}

Then you can use:

list.Sort(x=>x.SomeProp); // etc

This updates the existing list in the same way that List.Sort usually does.