Hi tricman10，

tricman10

 @Html.DropDownListFor(m => m.ExamDetails[i].Grade, Model.GradeItems, new { @id = "Grade_" + i })

Actually,this is a Inline problem,when the parameter is one of a multi-line collection,the dropdownlistfor does not know what should be selected.

tricman10

When I show files it always shows me the value 5. Not the value 6 in this example.</div>

So dropdownlistfor can only display the first one option of the GradesList(5) rather than 6.

I make a demo,you could refer to it:

Model:

       public class StudentCourse_VM
        {
            public List<Course> CourseList { get; set; }
            public IEnumerable<SelectListItem> GradeItems { get; set; }//5,6,7,8,9,10...

        }
        public class Course
        {
            public int CourseID { get; set; }
            public string CourseName { get; set; }
            public string CourseCode { get; set; }
        }

Controller:

      public ActionResult Index()
        {

            var GradesList = new List<SelectListItem>();

            for (int i = 5; i <= 10; i++)
            {
                GradesList.Add(new SelectListItem { Text = i.ToString(), Value = i.ToString() });
            }

            StudentCourse_VM vm = new StudentCourse_VM();

            vm.CourseList = new List<Course>() {
                new Course(){ CourseID= 6, CourseName = "CA", CourseCode="C001"},//I will test this line(CourseList[0]) in view
                new Course(){ CourseID= 7, CourseName = "CB", CourseCode="C002"},
                new Course(){ CourseID= 8, CourseName = "CC", CourseCode="C003"},
            };
            vm.GradeItems = GradesList;
            return View(vm);
        }

View:

@model TestApplication1.Controllers.HomeController.StudentCourse_VM
@{
    ViewBag.Title = "Index";
}

<h2>Index</h2>

//this is wrong,it shows 5
@Html.DropDownListFor(m => m.CourseList[0].CourseID, Model.GradeItems)

//this is right,it shows 6
@Html.DropDownListFor(m => m.CourseList[0].CourseID, 
                              Model.GradeItems.Select(y => new SelectListItem { Value = y.Value, Text = y.Text, Selected = (y.Value == Model.CourseList[0].CourseID.ToString()) }).ToList())

How my demo works:

Best Regards.

Yuki Tao