public Course GetCourseByCourseId(long courseId)
{
try
{
if (courseId < 0)
{
throw new ArgumentException();
}
Course course = _iCourseDao.GetCourseByCourseId(courseId);
//没查到该门课
if (course == null)
{
throw new CourseNotFoundException();
}
return(course);
}
catch
{
throw;
}
}
