How to recursively list all the files in a directory in C#?

Question

How to recursively list all the files in a directory and child directories in C#?

Answer 1

If you only need filenames and since I didn't really like most of the solutions here (feature-wise or readability-wise), how about this lazy one?

private void Foo()
{
  var files = GetAllFiles("pathToADirectory");
  foreach (string file in files)
  {
      // Use can use Path.GetFileName() or similar to extract just the filename if needed
      // You can break early and it won't still browse your whole disk since it's a lazy one
  }
}

/// The specified path is invalid (for example, it is on an unmapped drive).
/// The caller does not have the required permission.
///  is a file name.-or-A network error has occurred.
/// The specified path, file name, or both exceed the system-defined maximum length. For example, on Windows-based platforms, paths must be less than 248 characters and file names must be less than 260 characters.
///  is null.
///  is a zero-length string, contains only white space, or contains one or more invalid characters as defined by .
[NotNull]
public static IEnumerable GetAllFiles([NotNull] string directory)
{
  foreach (string file in Directory.GetFiles(directory))
  {
    yield return file; // includes the path
  }

  foreach (string subDir in Directory.GetDirectories(directory))
  {
    foreach (string subFile in GetAllFiles(subDir))
    {
      yield return subFile;
    }
  }
}