//实现接口方法
        public async Task <IEnumerable <Teacher> > GetTeachersAsync(TeacherDtoParameters teacherDtoParameters)
        {
            if (string.IsNullOrWhiteSpace(teacherDtoParameters.TeacherGenderDisplay) && string.IsNullOrWhiteSpace(teacherDtoParameters.SearchTerm))
            {
                return(await _context.Teachers.ToListAsync());
            }

            var teacherItems = _context.Teachers as IQueryable <Teacher>;

            if (!string.IsNullOrWhiteSpace(teacherDtoParameters.TeacherGenderDisplay))
            {
                teacherDtoParameters.TeacherGenderDisplay = teacherDtoParameters.TeacherGenderDisplay.Trim();

                var teacherGender = Enum.Parse <Gender>(teacherDtoParameters.TeacherGenderDisplay);

                teacherItems = teacherItems.Where(x => x.TeacherGender == teacherGender);
            }

            if (!string.IsNullOrWhiteSpace(teacherDtoParameters.SearchTerm))
            {
                teacherDtoParameters.SearchTerm = teacherDtoParameters.SearchTerm.Trim();

                teacherItems = teacherItems.Where(x => x.TeacherName.Contains(teacherDtoParameters.SearchTerm));
            }

            return(await teacherItems.ToListAsync());
        }
        public async Task <ActionResult <IEnumerable <TeacherDto> > > GetTeachers([FromQuery] TeacherDtoParameters teacherDtoParameters)
        {
            var teachers = await _teacherRepository.GetTeachersAsync(teacherDtoParameters);

            //为所有对象添加导航属性?
            foreach (var teacher in teachers)
            {
                teacher.Academy = await _academyRepository.GetAcademyAsync(teacher.AcademyId);
            }
            var teacherDtos = _mapper.Map <IEnumerable <TeacherDto> >(teachers);

            return(Ok(teacherDtos));
        }