/// <summary>
 /// 根据班级Id和删除标识获得学生集合
 /// </summary>
 /// <param name="classInfo_id">班级Id</param>
 /// <param name="delFlag">删除标识:0---未删除,1---已删除</param>
 /// <returns></returns>
 public List <Student> GetAllStudentByClassInfoId(int classInfo_id, int delFlag = 0)
 {
     return(idal_student.GetAllStudentByClassInfoId(classInfo_id, delFlag));
 }