Using Active Directory In ASP.NET - Enumerate Active Directory Users

// Disclaimer and Copyright Information
// ADSIObject.cs : 
//
// All rights reserved.
//
// Written by Pardesi Services, LLC
// Version 1.0
//
// Distribute freely, except: don't remove our name from the source or
// documentation (don't take credit for my work), mark your changes (don't
// get me blamed for your possible bugs), don't alter or remove this
// notice.
// No warrantee of any kind, express or implied, is included with this
// software; use at your own risk, responsibility for damages (if any) to
// anyone resulting from the use of this software rests entirely with the
// user.
//
// Send bug reports, bug fixes, enhancements, requests, flames, etc. to
// softomatix@pardesiservices.com
///////////////////////////////////////////////////////////////////////////////
//

using System;
using System.Diagnostics;
using System.Text;
using System.DirectoryServices;
using System.Xml;

namespace ASPNet_App
{
	/// <summary>
	/// 
	/// </summary>
	public abstract class ADSIObject
	{
		protected bool m_bInitialized = false;
		protected int m_nNumProperties = -1;
		protected XmlDocument m_obPropertiesDoc = null;
		public ADSIObject()
		{
			// 
			// TODO: Add constructor logic here
			//
		}

		/// <summary>
		/// 
		/// </summary>
		/// <param name="propColl"></param>
		/// <returns></returns>
		public virtual bool Initialize(ResultPropertyCollection propColl)
		{
			// Check if the input collection object is null or not.
			if (null == propColl)
			{
				return false;
			}

			XmlNode obTopNode;
			try
			{
				// Create XMl Document to store values.
				m_obPropertiesDoc = new XmlDocument();
				obTopNode = this.AppendTopLevelNode();
				if (null == obTopNode)
				{
					Trace.WriteLine("Failed to add top level node to xml document");
					return false;
				}
				// Iterate over each key in the collection.
				foreach (string strKey in propColl.PropertyNames)
				{
					foreach (object obProp in propColl[strKey])
					{
						this.AppendPropertyNode(obTopNode, strKey, obProp);
					}
				}

				// Process the XML Document to store the information in local variables.
				this.ProcessUserData();

				this.m_nNumProperties = propColl.PropertyNames.Count;
				this.m_bInitialized = true;
			}
			catch (Exception ex)
			{
				Trace.WriteLine(ex.Message);
				return false;
			}
			return true;
		}

		/// <summary>
		/// 
		/// </summary>
		/// <returns></returns>
		public XmlDocument GetProperties()
		{
			if (!m_bInitialized)
			{
				return null;
			}

			return m_obPropertiesDoc;
		}

		/// <summary>
		/// 
		/// </summary>
		public int NumProperties
		{
			get
			{
				return m_nNumProperties;
			}
		}

		/// <summary>
		/// 
		/// </summary>
		/// <returns></returns>
		protected virtual XmlNode AppendTopLevelNode()
		{
			XmlNode obTopNode = null;
			if (this.m_obPropertiesDoc == null)
			{
				return null;
			}

			StringBuilder strTopNode = new StringBuilder();
			strTopNode.Append ("<?xml version=\"1.0\" encoding=\"utf-8\" ?>");
			strTopNode.Append ("<adsi_object> </adsi_object>");

			try
			{
				m_obPropertiesDoc.LoadXml(strTopNode.ToString());
				obTopNode = m_obPropertiesDoc.SelectSingleNode("//adsi_object");
			}
			catch (Exception ex)
			{
				Trace.WriteLine(ex.Message);
				return null;
			}
			return obTopNode;
		}

		/// <summary>
		/// 
		/// </summary>
		/// <param name="strNode"></param>
		/// <param name="prop"></param>
		/// <returns></returns>
		protected bool AppendPropertyNode(XmlNode node, string strNode, object prop)
		{
			try
			{
				XmlElement elem = this.m_obPropertiesDoc.CreateElement(strNode);
				XmlAttribute attrib = this.m_obPropertiesDoc.CreateAttribute("type");
				attrib.InnerText = prop.GetType().ToString();

				// Append the value type attribute to element.
				elem.Attributes.Append(attrib);

				// Append the value now...
				elem.InnerText = prop.ToString();

				// Append this element to top node.
				node.AppendChild(elem);
			}
			catch (Exception ex)
			{
				Trace.WriteLine(ex.Message);
			}
			return true;
		}

		/// <summary>
		/// 
		/// </summary>
		protected virtual void ProcessUserData()
		{
		}

		/// <summary>
		/// 
		/// </summary>
		/// <param name="strQuery"></param>
		/// <param name="strVal"></param>
		protected void GetNodeValue(string strQuery, ref string strVal)
		{
			try
			{
				XmlNode node = this.m_obPropertiesDoc.SelectSingleNode(strQuery);
				strVal = node.InnerText;
			}
			catch (Exception ex)
			{
				Trace.WriteLine(ex.Message);
			}
		}
	}
}