How to recursively list all the files in and get the files “on going”

Question

I'm writing a program that needs to search a directory and all its sub directories for files that have a certain extension. This is going to be used both on a local, and a network drive, so performance is a bit of an issue.

i know i can use this kind of option:

  foreach (string file in Directory.EnumerateFiles(
        path, "*.*", SearchOption.AllDirectories))
    {
        ///
    }

but my folders gonna have a lot of files so i wondered how to imlement this kind of search that return the files "on going" instead on waiting until all the search will finish (something like Queue)

Answer 1

If you mean that your method should return them one by one (assuming you understood EnumerateFiles() does that already). Use yield return:

public IEnumerable<string > Foo(string path)
{
     foreach (string file in Directory.EnumerateFiles(
        path, "*.*", SearchOption.AllDirectories))
     {
         // Add additional logic if you need here
         yield return file;
      }
}

That way, if you run with foreach on your method you'll get each file at a time and you can add additional logic in the method.