C# - Liefert ein Dictionary Object von LDAP Userattributen

/// <summary>
/// Liefert ein Dictionary Object von LDAP Userattributen
/// </summary>
/// <param name="UserName">Der NT UserAccount</param>
/// <param name="UserProperties">Liste der zu ermittelnden Properties
/// <example>
///     System.Collections.Generic.Dictionary<string, object> UserAttributs = GetUserProperties(Environment.UserName,new List<string>(new string[] {"mail","cn", "lastlogon","distinguishedName"}));
/// </example>
/// <returns></returns>
public System.Collections.Generic.Dictionary<string, object> GetUserProperties(string UserName, List<string> UserProperties)
{
	DirectorySearcher Searcher = new DirectorySearcher();
	SearchResultCollection SearchResults = null;
	Searcher.Filter = "(&(objectclass=user)(cn=" + UserName + "))";
	for (int i = 0; i <= UserProperties.Count - 1; i++)
	{
		Searcher.PropertiesToLoad.Add(UserProperties[i]);
	}
	Searcher.SearchScope = SearchScope.Subtree;
			   
	System.DirectoryServices.DirectoryEntry adsiRoot = new System.DirectoryServices.DirectoryEntry("LDAP://RootDSE");
	Searcher.SearchRoot = new DirectoryEntry("LDAP://" + adsiRoot.Properties["defaultNamingContext"][0]);
	SearchResults = Searcher.FindAll();
	if (SearchResults.Count > 1)
	{
		return null;
	}
	else
	{
		System.Collections.Generic.Dictionary<string, object> UserPropertiesResults = new System.Collections.Generic.Dictionary<string, object>();
		foreach (SearchResult OutPut in SearchResults)
		{
			for (int i = 0; i <= UserProperties.Count - 1; i++)
			{
				try
				{
					UserPropertiesResults.Add(UserProperties[i], OutPut.Properties[UserProperties[i]][0]);
				}
				catch 
				{
					UserPropertiesResults.Add(UserProperties[i], null);
				}
			}
		}
		return UserPropertiesResults;
   }
}