Primär wird sie allerdings nur dann, wenn es noch keine primäre Adresse gibt!

static void createPartyAddress(Args _args)
{
    DirPartyTable dirPartyTable = DirPartyTable::findByNum("???100000");
    DirParty dirParty;
    DirPartyPostalAddressView dirPartyPostalAddressView;

    // Create instance of dirParty
    dirParty = DirParty::constructFromCommon(dirPartyTable, DirUtility::getCurrentDateTime(), dirPartyTable.partyType());

    // Create primary address
    dirPartyPostalAddressView.LocationName      = "Office";
    dirPartyPostalAddressView.City              = "Vienna";
    dirPartyPostalAddressView.Street            = "Kärtnerring";
    dirPartyPostalAddressView.StreetNumber      = "18";
    dirPartyPostalAddressView.CountryRegionId   = "AUT";
    dirPartyPostalAddressView.IsPrimary         = NoYes::Yes;

    dirParty.createOrUpdatePostalAddress(dirPartyPostalAddressView);
}