列出活动目录组的所有成员

我设法做到了。它仍然有一些问题,因为某些原因,一些广告集团,它不返回其一些成员。
如果有人知道更好的方法,请告诉我!

[Microsoft.SqlServer.Server.SqlFunction(FillRowMethodName = "fillRow")]
public static IEnumerable getNTGroupMembers(string groupName)
{
    SearchResult result;
    DirectorySearcher search = new DirectorySearcher();
    search.Filter = String.Format("(cn={0})", groupName);
    search.PropertiesToLoad.Add("member");
    result = search.FindOne();
    ArrayList userNames = new ArrayList();
    if (result != null)
    {
        for (int counter = 0; counter < result.Properties["member"].Count; counter++)
        {
            string st = (string) result.Properties["member"][counter];
            DirectoryEntry gpMemberEntry = new DirectoryEntry(("LDAP://" + st));
            if (!(gpMemberEntry == null))
            {
                PropertyCollection userProps = gpMemberEntry.Properties;
                object objUser = userProps["sAMAccountname"].Value;
                userNames.Add(objUser);
            }
        }
    }
    return userNames;
}
private static void fillRow(Object obj, out string user)
{
    object row = (object)obj;
    user = (string)row;
}