Nie ma elementu ViewData typu „IEnumerable ”, który ma klucz „CategoryID”

//In Controller Action

public ActionResult AddNewPost(string subName)

{

 ViewBag.Cats = new SelectList(db.Categories

 .Where(c=> c.Status)

 .Select(c=> new {CategoryID = c.YourCatIdField, 

 CategoryName = c.YourCatNameField},

 "CategoryID", "CategoryName");

 return View();

}//In View

@Html.DropDownList("myCatId", 

 (SelectList)(ViewData["Cats"]), "-- Select --")//Controller

[HttpPost]

public ActionResult AddNewPost(string subName, int myCatId)

{

//myCatId should bring the selected value here

}

@Html.DropDownListFor(item =>Model.CategoryID,ViewBag.CategoryId as SelectList,"-- Select --")

[httpGet]public ActionResult AddNewPost(string subName)

 {

 ViewBag.CategoryID = new SelectList(from c in db.Categories where c.Status == true select c, "CategoryID", "CategoryName");

 return View();

 }

[HttpPost]

public ActionResult AddNewPost(string subName,ur model)

 {

 model.add(model); 

 ViewBag.CategoryID = new SelectList(from c in db.Categories where c.Status == true select c, "CategoryID", "CategoryName");

 return View();

 }

public int? CategoryId {get;set;}