使用List <>中的映射和索引收集目录和子目录

Question

I want to collect the directory listing in a collection(a List<> perhaps) my directory structure is like :

MainFolder\ParentFolder1\SubFolder1    
                        \SubFolder2    
                        \SubFolder3

MainFolder\ParentFolder2\SubFolder1
                        \SubFolder2
                        \SubFolder3

I want to list all the subfolders mapped to their parent directories.

Also, the records will have index of ParentFolder 0-n in MainFolder and index of SubFolder 0-n in each ParentFolder.

I did tried below but not yet achieved

lstParents = (from f in Directory.GetDirectories(MainFolder)
             select  Data
         {
        parent =f
         }).ToList();

var lstSubDir = (from f in lstParents.Select(m => Directory.GetDirectories(m.parent).ToList());

Answer 1

You can use this overload of the GetDirectories method to find all subdirectories recursively:

var mainDirectory = new DirectoryInfo(@"C:\temp\MainFolder");
var subDirectories = mainDirectory.GetDirectories("*", SearchOption.AllDirectories);

Then you can map them into pairs of directory/parent like this:

var mappedDirectories = subDirectories.Select(sd => new { Parent=sd.Parent, Child=sd });

If you want to exclude the first level of subdirectories ( ParentFolder1 and ParentFolder2 , in your case) you can filter them like this:

var mappedDirectories = subDirectories
    .Where(sd => sd.Parent.FullName != mainDirectory.FullName)
    .Select(sd => new { Parent=sd.Parent, Child=sd });

EDIT after you've asked for indices:

You stated, that you'll always only have a nesting level of 2, the following piece of code will not work for deeper directory structures.

var mainDirectory = new DirectoryInfo(@"C:\temp\MainFolder");
var firstLevelDirectories = mainDirectory.GetDirectories().Select((f1,i) => new { 
  Parent = f1, 
  ParentIndex = i 
});

var secondLevelDirectories = firstLevelDirectories
  .SelectMany(f1 => f1.Parent.GetDirectories().Select((f2,i) => new {
    f1.Parent, 
    f1.ParentIndex, 
    Child = f2, 
    ChildIndex = i
} ));

This will give you a list of records, each containing

• the parent directory,
• the parent directory index,
• the child directory and
• the child directory index within its parent.

Answer 2

Try this recursive algorithm.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;

namespace ConsoleApplication2
{
    class Program
    {
        static void Main(string[] args)
        {
            Folders folders = new Folders(@"c:\temp", null);
            Console.ReadLine();
        }
    }
    public class Folders
    {
        public string path { get; set; }
        List<string> files = new List<string>();
        List<Folders> folders = new List<Folders>();
        Folders parent = null;

        public Folders(string path, Folders parent)
        {
            this.parent = parent;
            this.path = path;
            foreach (string folderPath in Directory.GetDirectories(path))
            {
                Folders newFolder = new Folders(folderPath, this);
                folders.Add(newFolder);
            }
            files = Directory.GetFiles(path).ToList();
            int pathlength = path.Length;
            Boolean first = true;
            Console.Write(path);
            if (files.Count == 0) Console.WriteLine();
            foreach (string file in files)
            {
                string shortname = file.Substring(file.LastIndexOf("\\") + 1);
                if (first)
                {
                    Console.WriteLine("\\" + shortname);
                    first = false;
                }
                else
                {

                    Console.WriteLine(new string(' ', pathlength + 1) + shortname);
                }
            }

        }
    }
}
​