我想使用C#从Active Directory获取增量更改。为此，我正试图构建一个解决方案，如以下文章所述。

https://docs.microsoft.com/en-us/windows/win32/ad/polling-for-changes-using-usnchanged

然而，我面临以下问题：

1. 用户没有可用的uSNChanged属性（尽管它可用于OU，即OrganizationalUnit）。我只能看到用户的以下属性

当我将用户从OU1移动到OU2时，highestcommittedusn会增加，但当我查询更改时（search.Filter=“（uSNChanged

同样的情况也适用于在OU中添加用户。

示例代码如下所述：

public static void GetUpdates()
{
    var myLdapConnection = createDirectoryEntry();
    var search = new DirectorySearcher(myLdapConnection);
    search.Filter = "(uSNChanged>=13000)";
    search.SearchScope = System.DirectoryServices.SearchScope.Subtree;
    var results = search.FindAll();
    Console.WriteLine(results.Count);
}

public static DirectoryEntry createDirectoryEntry()
{
    DirectoryEntry ldapConnection = new DirectoryEntry("LDAP://adfs.fed.abcd.com/DC=adfs,DC=fed,DC=abcd,DC=com");
    ldapConnection.Path = "adfs.fed.abcd.com";
    ldapConnection.AuthenticationType = AuthenticationTypes.Secure;
            return ldapConnection;
}

 private static long GetHighestUsn()
 {
     using (LdapConnection connection = new LdapConnection(ldapPath))
     {
          var filter = "(&(objectClass=*))";
          var searchRequest = new SearchRequest(null, filter, System.DirectoryServices.Protocols.SearchScope.Base, "highestCommittedUSN");
          var response = connection.SendRequest(searchRequest) as SearchResponse;
          var usn = response.Entries[0].Attributes["highestcommittedusn"][0];
          return Convert.ToInt64(usn);
      }
      return 0;
}

非常感谢您的帮助。