Use Directory.GetDirectories to get the subdirectories of the directory specified by "your_directory_path". The result is an array of strings.

var directories = Directory.GetDirectories("your_directory_path");

By default, that only returns subdirectories one level deep. There are options to return all recursively and to filter the results, documented here, and shown in Clive's answer.

Avoiding an UnauthorizedAccessException

It's easily possible that you'll get an UnauthorizedAccessException if you hit a directory to which you don't have access.

You may have to create your own method that handles the exception, like this:

public class CustomSearcher
{
public static List<string> GetDirectories(string path, string searchPattern = "*",
SearchOption searchOption = SearchOption.AllDirectories)
{
if (searchOption == SearchOption.TopDirectoryOnly)
return Directory.GetDirectories(path, searchPattern).ToList();


var directories = new List<string>(GetDirectories(path, searchPattern));


for (var i = 0; i < directories.Count; i++)
directories.AddRange(GetDirectories(directories[i], searchPattern));


return directories;
}


private static List<string> GetDirectories(string path, string searchPattern)
{
try
{
return Directory.GetDirectories(path, searchPattern).ToList();
}
catch (UnauthorizedAccessException)
{
return new List<string>();
}
}
}

And then call it like this:

var directories = CustomSearcher.GetDirectories("your_directory_path");

This traverses a directory and all its subdirectories recursively. If it hits a subdirectory that it cannot access, something that would've thrown an UnauthorizedAccessException, it catches the exception and just returns an empty list for that inaccessible directory. Then it continues on to the next subdirectory.

Easy as this:

string[] folders = System.IO.Directory.GetDirectories(@"C:\My Sample Path\","*", System.IO.SearchOption.AllDirectories);

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


namespace TRIAL
{
public class Class1
{
static void Main(string[] args)
{
string[] fileArray = Directory.GetDirectories("YOUR PATH");
for (int i = 0; i < fileArray.Length; i++)
{


Console.WriteLine(fileArray[i]);
}
Console.ReadLine();
}
}
}

FolderBrowserDialog fbd = new FolderBrowserDialog();


DialogResult result = fbd.ShowDialog();


string[] files = Directory.GetFiles(fbd.SelectedPath);
string[] dirs = Directory.GetDirectories(fbd.SelectedPath);


foreach (string item2 in dirs)
{
FileInfo f = new FileInfo(item2);


listBox1.Items.Add(f.Name);


}


foreach (string item in files)
{
FileInfo f = new FileInfo(item);


listBox1.Items.Add(f.Name);


}

show all directry and sub directories

def dir():

from glob import glob


dir = []


dir = glob("path")


def all_sub_dir(dir):
{


for item in dir:


{
b = "{}\*".format(item)
dir += glob(b)
}
print(dir)
}

To just get the simple list of folders without full path, you can use:

Directory.GetDirectories(parentDirectory).Select(d => Path.GetRelativePath(parentDirectory, d)

Here's Best and Fastest Way To List All Directories and Subdirectories by Skipping System.UnauthorizedAccessException

A simple recursive method with action to retrieve at realtime, preparing a list and returning to parent takes a lot of time, this call back function helps a lot to retrieve at realtime instead of preparing and returning back

using System.IO;


private static void ListDirectories(string Path, Action<string> Listen){
try
{
foreach(string Node in Directory.GetDirectories(Path)){
Listen(Node);
ListDirectories(Node, Listen);
}
} catch {}
}

Usase

static void Main(string[] args)
{
ListDirectories(@"C:\", (dir) =>
{
Console.WriteLine(dir);
});
}