User ID to user name or Worker Name in AX 2012 / D365

Hi,

Worker = HcmWorker::find(DirPersonUser::findUserWorkerReference(UserId));

or

    public display Name userName()
{
    DirPartyName        partyName;

    partyName = DirPersonUser::userId2Name(this.UserId);
    if (!partyName)
        partyName = (select firstonly Name from userInfo where userInfo.Id == this.UserId).Name;
    if (!partyName)
        partyName = this.UserId;
    return partyName;
}

Regards