Active Directory: Get All Users with C#

Active Directory get all users with c#

A simple ADUser class that will read all users of an active directory. The sample code only reads CN and sAMAccountName but more properties can be added.

using System.Collections.Generic;
using System.DirectoryServices;
 
namespace ActiveDirectory
{
    /// <summary>
    /// Active Directory User.
    /// </summary>
    public class  ADUser
    {
        #region constants
 
        /// <summary>
        /// Property name of sAM account name.
        /// </summary>
        public const  string SamAccountNameProperty = "sAMAccountName";
 
        /// <summary>
        /// Property name of canonical name.
        /// </summary>
        public const  string CanonicalNameProperty = "CN";
 
        #endregion
 
        #region Properties
 
        /// <summary>
        /// Gets or sets the canonical name of the user.
        /// </summary>
        public string  CN { get; set; }
 
        /// <summary>
        /// Gets or sets the sAM account name
        /// </summary>
        public string  SamAcountName { get; set; }
 
        #endregion
 
        /// <summary>
        /// Gets all users of a given domain.
        /// </summary>
        /// <param name="domain">Domain to query. Should be given in the form ldap://domain.com/ </param>
        /// <returns>A list of users.</returns>
        public static  List<ADUser> GetUsers(string domain)
        {
            List<ADUser> users = new  List<ADUser>();
 
            using (DirectoryEntry searchRoot = new DirectoryEntry(domain))
            using (DirectorySearcher directorySearcher = new DirectorySearcher(searchRoot))
            {
                // Set the filter
                directorySearcher.Filter = "(&(objectCategory=person)(objectClass=user))";
 
                // Set the properties to load.
                directorySearcher.PropertiesToLoad.Add(CanonicalNameProperty);
                directorySearcher.PropertiesToLoad.Add(SamAccountNameProperty);
 
                using (SearchResultCollection searchResultCollection = directorySearcher.FindAll())
                {
                    foreach (SearchResult searchResult in searchResultCollection)
                    {
                        // Create new ADUser instance
                        var user = new  ADUser();
 
                        // Set CN if available.
                        if (searchResult.Properties[CanonicalNameProperty].Count > 0)
                            user.CN = searchResult.Properties[CanonicalNameProperty][0].ToString();
 
                        // Set sAMAccountName if available
                        if (searchResult.Properties[SamAccountNameProperty].Count > 0)
                            user.SamAcountName = searchResult.Properties[SamAccountNameProperty][0].ToString();
 
                        // Add user to users list.
                        users.Add(user);
                    }
                }
            }
 
            // Return all found users.
            return users;
        }
    }
}

A small example on using this could be:

using Microsoft.VisualStudio.TestTools.UnitTesting;
using ActiveDirectory;
 
namespace Tests
{
    /// <summary>
    /// Tests the ActiveDirectory classes.
    /// </summary>
    [TestClass]
    public class  ActiveDirectoryTests
    {
        /// <summary>
        /// Tests the <see cref="ADUser"/> class
        /// </summary>
        [TestMethod]
        public void  TestADUser()
        {
            var users = ADUser.GetUsers("LDAP://neitzel.local/DC=neitzel,DC=local");
            Assert.IsNotNull(users);
        }
    }
}