public GradePhyStandard GetStandard(GradePhySubject subject, UserGradeBaseInfo userBaseInfo) { if (subject == null || userBaseInfo == null) { return(null); } var userAge = userBaseInfo.Time_BirthDay.Age(); subject.Standards = subject.Standards; foreach (var i in subject.Standards) { if (i.gender == userBaseInfo.Gender && i.minAge <= userAge && i.maxAge >= userAge) { return(i); } } return(null); }