Improve the performance for enumerating files and folders using .NET

Question

I have a base directory that contains several thousand folders. Inside of these folders there can be between 1 and 20 subfolders that contains between 1 and 10 files. I\'d

Answer 1

You are using a Linq. It would be faster if you wrote your own method for searching Directories recursively with you're special case.

public static DateTime retval = DateTime.Now.AddDays(-60);

public static void WalkDirectoryTree(System.IO.DirectoryInfo root)
{
    System.IO.FileInfo[] files = null;
    System.IO.DirectoryInfo[] subDirs = null;

    // First, process all the files directly under this folder 
    try
    {
        files = root.GetFiles("*.*");
    }
    // This is thrown if even one of the files requires permissions greater 
    // than the application provides. 
    catch (UnauthorizedAccessException e)
    {
        // This code just writes out the message and continues to recurse. 
        // You may decide to do something different here. For example, you 
        // can try to elevate your privileges and access the file again.
        log.Add(e.Message);
    }
    catch (System.IO.DirectoryNotFoundException e)
    {
        Console.WriteLine(e.Message);
    }

    if (files != null)
    {
        foreach (System.IO.FileInfo fi in files)
        {
          if (fi.LastWriteTime < retval)
          {
            oldFiles.Add(files[i]);
          }

            Console.WriteLine(fi.FullName);
        }

        // Now find all the subdirectories under this directory.
        subDirs = root.GetDirectories();

        foreach (System.IO.DirectoryInfo dirInfo in subDirs)
        {
            // Resursive call for each subdirectory.
            WalkDirectoryTree(dirInfo);
        }
    }            
}