Listing windows user accounts using C#

Question

Hi,

I have to list all users (both local system and domain). I tried using WQL but it takes a lot of time for the program to run. Is there any other way to get it from registry? Any help would be appreciated.

Answer 1

using System;
using System.Collections.Generic;
using System.DirectoryServices;
namespace ListADUsers.ConsoleApp
{
    class Program
    {
     static void Main(string[] args)
     {
      Console.Clear();
      IList<String> userList = new List<String>();
      int badEntries = 0;
      string domainName = String.Empty;
      if (args.Length > 0)
       domainName = args[0];
      else
      {
       Console.Write("\nPlease enter your Active Directory domain name: ");
       domainName = Console.ReadLine();
      }
      Console.Write(String.Format("\nAttempting to build user list for {0} ...\n\n", domainName));
      try
      {
       if (!String.IsNullOrEmpty(domainName))
       {
        DirectoryEntry myDirectoryEntry = new DirectoryEntry(String.Format("LDAP://{0}", domainName));
        DirectorySearcher mySearcher = new DirectorySearcher(myDirectoryEntry);
        SortOption mySort = new SortOption("sn", SortDirection.Ascending);
        mySearcher.Filter = ("(objectCategory=person)");
        mySearcher.Sort = mySort;
        foreach (SearchResult resEnt in mySearcher.FindAll())
        {
         try
         {
          if (!String.IsNullOrEmpty(resEnt.Properties["Mail"][0].ToString())
           && System.Text.RegularExpressions.Regex.IsMatch(resEnt.Properties["DisplayName"][0].ToString(), " |admin|test|service|system|[$]", System.Text.RegularExpressions.RegexOptions.IgnoreCase)
           )
           {
            int space = resEnt.Properties["DisplayName"][0].ToString().IndexOf(" ");
            string formattedName = String.Format("{0}{1}{2}",
             resEnt.Properties["DisplayName"][0].ToString().Substring(space).PadRight(25),
             resEnt.Properties["DisplayName"][0].ToString().Substring(0, space).PadRight(15),
             resEnt.Properties["Mail"][0].ToString()
             );
            userList.Add(formattedName);
           }
         }
         catch
         {
          badEntries++;
         }
        }
        if (userList.Count > 0)
        {
         Console.WriteLine(String.Format("=========== Listing of users in the {0} domain\n", domainName));
         Console.WriteLine(String.Format("{0}{1}{2}", "Surname".PadRight(25), "First Name".PadRight(15), "Email Address\n"));
         for (int i = 0; i < userList.Count - 1; i++)
          Console.WriteLine(userList[i].ToString());
         Console.WriteLine(String.Format("\n=========== {0} users found in the {1} domain", userList.Count.ToString(), domainName));
        }
        else
         Console.WriteLine(String.Format("\n=========== 0 users found in the {0} domain", userList.Count.ToString()));
        Console.WriteLine(String.Format("=========== {0} objects could not be read", badEntries.ToString()));
        Console.WriteLine("=========== End of Listing");
       }
       else
       {
        Console.WriteLine("Please enter a domain name next time!");
       }
      }
      catch (Exception ex)
      {
       // in a production app you wouldn't show the user the exception details
       Console.Write(String.Format("A critical error occurred.\nDetails: {0}", ex.Message.ToString()));
      }
     }
    }
}

Download sample application : Sample Application to List AD Users

Source : Follow Up – List active directory users – This time in C#