public async Task CountPresentationGradeAsync(long seminarId) { //调用TopicService 的 IList<Topic> ListTopicBySeminarIdAsync(long seminarId)方法 var topicList = await _iTopicService.ListTopicBySeminarIdAsync(seminarId); //调用自己的dao分别对每个topic计算 await _iGradeDao.CountPresentationGradeAsync(seminarId, topicList); }