dropdownlist set selected value in MVC3 Razor

Question

Here is my model:

public class NewsCategoriesModel {     public int NewsCategoriesID { get; set; }             public string NewsCategoriesName { get; set; } } 

My controller:

public ActionResult NewsEdit(int ID, dms_New dsn) {     dsn = (from a in dc.dms_News where a.NewsID == ID select a).FirstOrDefault();     var categories = (from b in dc.dms_NewsCategories select b).ToList();     var selectedValue = dsn.NewsCategoriesID;     SelectList ListCategories = new SelectList(categories, "NewsCategoriesID", "NewsCategoriesName",selectedValue);      // ViewBag.NewsCategoriesID = new SelectList(categories as IEnumerable<dms_NewsCategory>, "NewsCategoriesID", "NewsCategoriesName", dsn.NewsCategoriesID);     ViewBag.NewsCategoriesID = ListCategories;     return View(dsn); } 

And then my view:

@Html.DropDownList("NewsCategoriesID", (SelectList)ViewBag.NewsCategoriesID) 

When i run, the DropDownList does not select the value I set.. It is always selecting the first option.

Answer 1

You should use view models and forget about ViewBag Think of it as if it didn't exist. You will see how easier things will become. So define a view model:

public class MyViewModel {     public int SelectedCategoryId { get; set; }     public IEnumerable<SelectListItem> Categories { get; set; }  } 

and then populate this view model from the controller:

public ActionResult NewsEdit(int ID, dms_New dsn) {     var dsn = (from a in dc.dms_News where a.NewsID == ID select a).FirstOrDefault();     var categories = (from b in dc.dms_NewsCategories select b).ToList();      var model = new MyViewModel     {         SelectedCategoryId = dsn.NewsCategoriesID,         Categories = categories.Select(x => new SelectListItem         {             Value = x.NewsCategoriesID.ToString(),             Text = x.NewsCategoriesName         })     };     return View(model); } 

and finally in your view use the strongly typed DropDownListFor helper:

@model MyViewModel  @Html.DropDownListFor(     x => x.SelectedCategoryId,     Model.Categories )