There is no ViewData item with the key '--' of type IEnumerable

There is no ViewData item with the key 'Student-Id' of type IEnumerable<SelectListItem> 


I got the above error when I wrote below code to bind data in DropdownList.

In View

<%= Html.DropDownListFor(x =>.Student_Id,<SelectList>ViewData["StudentList"])%>


In Controller

 TestMVCEntities3 DBobj = new TestMVCEntities3();
 ViewData["StudentList"] = new SelectList(DBobj.Student, "Student_Id","Name");  
 return View();

I Resolved the above error by Using Model instead of ViewData in below manner

In View

<%= Html.DropDownListFor(x => x.Student_Id,Model.StudentList)%>


In Model
public IEnumerable<SelectListItem> StudentList { get; set; }


In Controller

 TestMVCEntities3 DBobj = new TestMVCEntities3();
 var model = new StudentMarksModel();
 model.StudentList = new SelectList(DBobj.Student, "Student_Id", "Name");
 return View(model);