Custom Linq Ordering

Question

I have over a thousand folders, each folder contains one or more files with the following names:

Unordered:

Alison.ext
Heather.ext
Molly.ext
Paula.ext
Sam.ext         


        

Answer 1

List sortKeys = new List { 'M', 'S', 'H', 'A', 'P' };
sortKeys.Reverse();
List files = new List(6);

foreach(char sortKey in sortKeys)
{
    var topFiles = files.Where(file => file.Name.StartsWith(sortKey.ToString()));
    var remainingFiles = files.Except(topFiles);
    files = topFiles.Concat(remainingFiles).ToList();
}

Untested and I'm sure there are faster ways, but at least it's with linq stuff as you asked :-)

edit: I just saw the edit on your post and now I don't have any idea anymore what you really want to do, so my code is probably useless to you..