//查询当门课学生名字和学号
public List <Check> StudentInfo(String teaid, string couid, string counm)
{
DataTable dt = teacherDao.StudentNumber(teaid, couid, counm);
CommonLeiconvertTable <Check> ConTable = new CommonLeiconvertTable <Check>();
List <Check> list = ConTable.ConvertToList(dt);
return(list);
}