//选课处理页
public void SelectingCourse(string id)
{
//课程表选课人数增加
Course course = entity.Courses.Where(p => p.CId == id).FirstOrDefault();
int num = course.CNum;
//选课人数必须少于等于50人
if (num < 50)
{
num++;
course.CNum = num;
entity.Entry <Course>(course).State = System.Data.EntityState.Modified;
int j = entity.SaveChanges();
if (j != 0)
{
//添加选课记录
SeleCourse se = new SeleCourse();
se.CId = id;
se.SId = Convert.ToString(Session["SId"]);
se.SCGrade = 0;
entity.SeleCourses.Add(se);
int i = entity.SaveChanges();
if (i != 0)
{
Response.Write(JsHelper.Messagebox("选课成功！", "Student", "Index"));
}
else
{
//添加选课记录失败后，课程表还原
num--;
course.CNum = num;
entity.Entry <Course>(course).State = System.Data.EntityState.Modified;
entity.SaveChanges();
Response.Write(JsHelper.Messagebox("选课失败！", "Student", "Index"));
}
}
else
{
Response.Write(JsHelper.Messagebox("选课失败！", "Student", "Index"));
}
}
else
{
Response.Write(JsHelper.Messagebox("选课人数过多，选课失败！", "Student", "Index"));
}
}
//退选课程处理页
public void UnselectedCourse(string id)
{
//选课记录表删除记录
string sid = Convert.ToString(Session["SId"]);
SeleCourse selecourse = entity.SeleCourses.Where(p => p.CId == id && p.SId == sid).FirstOrDefault();
entity.SeleCourses.Remove(selecourse);
int i = entity.SaveChanges();
if (i != 0)
{
//课程表选课人数减少
Course course = entity.Courses.Where(p => p.CId == id).FirstOrDefault();
int num = course.CNum;
num--;
course.CNum = num;
entity.Entry <Course>(course).State = System.Data.EntityState.Modified;
int j = entity.SaveChanges();
if (j != 0)
{
Response.Write(JsHelper.Messagebox("退课成功！", "Student", "Index"));
}
else
{
//选课记录表还原
SeleCourse se = new SeleCourse();
se.CId = id;
se.SId = Convert.ToString(Session["SId"]);
se.SCGrade = 0;
entity.SeleCourses.Add(se);
entity.SaveChanges();
Response.Write(JsHelper.Messagebox("退课失败！", "Student", "Index"));
}
}
else
{
Response.Write(JsHelper.Messagebox("退课失败！", "Student", "Index"));
}
}