extensions/ActiveDirectoryExtensions.cs

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

namespace Chrosey.Extensions
{
    public static class ActiveDirectoryExtensions
    {
        public static T Get<T>(this DirectoryEntry entry, string propertyName) where T : class
        {
            if (string.IsNullOrWhiteSpace(propertyName)) throw new ArgumentNullException("propertyName darf nicht leer sein");
            if (!entry.Properties.PropertyNames.Cast<string>().Contains(propertyName)) return null;

            return entry.Properties[propertyName].Value as T;
        }

        public static string GetValue(this DirectoryEntry entry, string propertyName)
        {
            try
            {
                if (string.IsNullOrEmpty(propertyName)) throw new ArgumentNullException("Der PropertyName[" + propertyName + "] kann nicht null oder leer sein");
                if (null == entry) throw new ArgumentNullException("Kann keine Eigenschaft von null abrufen");
                if (!entry.Properties.Contains(propertyName)) return string.Empty;

                return entry.Properties[propertyName].Value.ToString();
                
            }
            catch (Exception e)
            {
                throw new FieldAccessException(string.Format("Fehler beim Lesen von {0}.{1}",entry.Name,propertyName), e);
            }
        }
        public static byte[] Photo(this DirectoryEntry entry)
        {
            try
            {
                if (null == entry) throw new ArgumentNullException("Kann keine Eigenschaft von null abrufen");
                if (!entry.Properties.Contains("thumbnailPhoto")) return null;

                return entry.Properties["thumbnailPhoto"].Value as byte[];

            }
            catch (Exception e)
            {
                throw new FieldAccessException(string.Format("Fehler beim Lesen von {0}.{1}", entry.Name, "thumbnailPhoto"), e);
            }
        }

        public static string GetValue(this SearchResult sr, string propertyName)
        {
            if (string.IsNullOrEmpty(propertyName)) throw new ArgumentNullException("Der PropertyName[" + propertyName + "] kann nicht null oder leer sein");
            if (null == sr) throw new ArgumentNullException("Kann keine Eigenschaft von null abrufen");
            
            try
            {
                var s = sr.Properties[propertyName.ToLower()];
                if (s.Count > 0)
                {
                    return s[0].ToString();
                }
                return string.Empty;
            }
            catch (Exception e)
            {
                throw new FieldAccessException(string.Format("Fehler beim Lesen von {0}.{1}", sr.Path, propertyName), e);
            }
        }
    }
}