如何在Active Directory中获取用户组？(c#,asp.net)

using System.DirectoryServices.AccountManagement;

public List<string> GetUserGroups(string username)
{
    List<string> groups = new List<string>();

    try
    {
        using (PrincipalContext pc = new PrincipalContext(ContextType.Domain))
        {
            UserPrincipal user = UserPrincipal.FindByIdentity(pc, username);

            if (user != null)
            {
                PrincipalSearchResult<Principal> results = user.GetAuthorizationGroups();

                foreach (Principal p in results)
                {
                    groups.Add(p.Name);
                }
            }
        }
    }
    catch (Exception ex)
    {
        // 处理异常
    }

    return groups;
}