C# Student.IsEnrolledIn方法代码示例

    //**************************************
    //    
    public EnrollFlags Enroll(Student s)
    {
        // First, make sure that this Student is not already
        // enrolled for this Section, has not already enrolled
        // in another section of this class and that he/she has
        // NEVER taken and passed the course before.

        Transcript transcript = s.Transcript;

        if (s.IsEnrolledIn(this) ||
            s.IsCurrentlyEnrolledInSimilar(this) ||
            transcript.VerifyCompletion(RepresentedCourse))
        {
            return EnrollFlags.PREVIOUSLY_ENROLLED;
        }

        // If there are any prerequisites for this course,
        // check to ensure that the Student has completed them.

        Course c = RepresentedCourse;
        if (c.HasPrerequisites())
        {

            foreach (Course pre in c.Prerequisites)
            {

                // See if the Student's Transcript reflects
                // successful completion of the prerequisite.

                if (!transcript.VerifyCompletion(pre))
                {
                    return EnrollFlags.PREREQ_NOT_SATISFIED;
                }
            }
        }

        // If the total enrollment is already at the
        // the capacity for this Section, we reject this
        // enrollment request.

        if (!ConfirmSeatAvailability())
        {
            return EnrollFlags.SECTION_FULL;
        }

        // If we made it to here in the code, we're ready to
        // officially enroll the Student.

        // Note bidirectionality:  this Section holds
        // onto the Student via the Dictionary, and then
        // the Student is given an object reference to this Section.

        if (!EnrolledStudents.ContainsKey(s.Id))
        {
            EnrolledStudents.Add(s.Id, s);
        }

        s.AddSection(this);
        return EnrollFlags.SUCCESSFULLY_ENROLLED;
    }

    //**************************************
    //    
    public bool Drop(Student s)
    {
        // We may only drop a student if he/she is enrolled.

        if (!s.IsEnrolledIn(this))
        {
            return false;
        }
        else
        {
            // Find the student in our Dictionary, and remove it.

            EnrolledStudents.Remove(s.Id);

            // Note bidirectionality.

            s.DropSection(this);
            return true;
        }
    }