C# - Liefert ein Attribut Objekt eines LDAP Objects (cn)

/// <summary>
/// Liefert ein Object mit dem einzelnen LDAP-Wert für ein eindeutiges LDAP-Object (cn).
/// Ist null wenn a)das Object nicht gefunden wurde oder b)mehrere Einträge existieren.
/// </summary>
/// <param name="LDAPcn">Der cn-Name.</param>
/// <param name="Property">Das gewünschte Property-Attribut.</param>
/// <param name="objectClass">Die AD ObjectClass. Mögliche Werte "computer", "user", "group","organizationalunit" oder null. </param>
/// <param name="LDAPEntryPoint">Der LDAP Einstiegspunkt oder null</param>
/// <example>
///     object up = GetLDAPValue(Environment.UserName, "mail","user",null);
/// </example>
public object GetLDAPValue(string LDAPcn, string Property, string objectClass, string LDAPEntryPoint)
{
	DirectorySearcher Searcher = new DirectorySearcher();
	SearchResultCollection SearchResults;
	if (objectClass == null)
	{
		Searcher.Filter = "(cn=" + LDAPcn + ")";
	}
	else
	{
		objectClass = objectClass.ToUpper();
		switch (objectClass)
		{
			case "COMPUTER":
				Searcher.Filter = "(&(objectClass=computer)(cn=" + LDAPcn + "))";
				break;
			case "USER":
				Searcher.Filter = "(&(objectClass=user)(cn=" + LDAPcn + "))";
				break;
			case "GROUP":
				Searcher.Filter = "(&(objectClass=group)(cn=" + LDAPcn + "))";
				break;
			case "ORGANIZATIONALUNIT":
				Searcher.Filter = "(&(objectClass=organizationalUnit)(cn=" + LDAPcn + "))";
				break;
	   }
	}
	Searcher.PropertiesToLoad.Add(Property);
	Searcher.SearchScope = SearchScope.Subtree;
	if (LDAPEntryPoint == null)
	{
		System.DirectoryServices.DirectoryEntry adsiRoot = new System.DirectoryServices.DirectoryEntry("LDAP://RootDSE");
		LDAPEntryPoint = "LDAP://" + adsiRoot.Properties["defaultNamingContext"][0];
	}
	Searcher.SearchRoot = new DirectoryEntry(LDAPEntryPoint);
	SearchResults = Searcher.FindAll();
	if (SearchResults.Count > 1)
	{
		return null;
	}
	else
	{
		foreach (SearchResult OutPut in SearchResults)
		{
			try
			{
				return OutPut.Properties[Property][0];
			}
			catch
			{
				return null;
			}
		}
	}
	return null;
}