/// <summary>
 /// 创建考试信息
 /// 需要班级时间科目
 /// </summary>
 /// <returns></returns>
 public static async Task CreateExam(Guid clsId, Guid subjectId, DateTime examTime)
 {
     using (var examSvc = new ExamService())
     {
         await examSvc.CreateAsync(new Exam()
         {
             ClassId   = clsId,
             SubjectId = subjectId,
             ExamTime  = examTime
         });
     }
 }