How To Use More Than One Condition in CASE Stateme

问题:

I want to use following conditions in one CASE how can i do that

((LTRIM(RTRIM(AdvertisementAuthorityAfterDateOfPublication.AAADPPapCode)) = (LTRIM(RTRIM(@PapCode)))) AND
(DATEDIFF(DAY,(CONVERT(date,@PubDate,111)),(CONVERT(date,CURRENT_TIMESTAMP,111)))) > (AdvertisementAuthorityAfterDateOfPublication.AAADPAddNoOfDates)
AND
(LTRIM(RTRIM(AdvertisementAuthorityAfterDateOfPublication.AAADPSysOperator))) != (LTRIM(RTRIM(@UserName))))

I try following way but I got Error

SELECT CASE
        WHEN ((LTRIM(RTRIM(AdvertisementAuthorityAfterDateOfPublication.AAADPPapCode)) = (LTRIM(RTRIM(@PapCode))))
          AND (DATEDIFF(DAY, (CONVERT(date, @PubDate, 111)), (CONVERT(date, CURRENT_TIMESTAMP, 111)))) > (AdvertisementAuthorityAfterDateOfPublication.AAADPAddNoOfDates)
          AND (LTRIM(RTRIM(AdvertisementAuthorityAfterDateOfPublication.AAADPSysOperator))) != (LTRIM(RTRIM(@UserName))))
          IS NULL THEN 1

   AS ErrorTag;