How to read File names recursively from subfolder using LINQ

Question

How to read file name with dll extension from a directory and from its subfolders recursively using LINQ or LAMBDA expression.

Now i\'m using Nested for

Answer 1

If you really want to do it with a recursive lambda expression here you go:

Action> discoverFiles = null;

discoverFiles = new Action>((dir, list) =>
    {
        try
        {
            foreach (var subDir in Directory.GetDirectories(dir))
                discoverFiles(string.Concat(subDir), list);

            foreach (var dllFile in Directory.GetFiles(dir, "*.dll"))
            {
                var fileNameOnly = Path.GetFileName(dllFile);
                if (!list.Contains(fileNameOnly))
                    list.Add(fileNameOnly);
            }
        }
        catch (IOException)
        {
            // decide what to do here
        }
    });

// usage:
var targetList = new List();
discoverFiles("c:\\MyDirectory", targetList);

foreach (var item in targetList)
    Debug.WriteLine(item);

Note: this is probably several times slower (and way harder to read/debug/maintain) than the previous answers, but it does not stop if there is an I/O exception somewhere.