MVC DropDownList SelectedValue not displaying correctly

by

The last argument of the SelectList constructor (in which you hope to be able to pass the selected value id) is ignored because the DropDownListFor helper uses the lambda expression you passed as first argument and uses the value of the specific property.

So here’s the ugly way to do that:

Model:

public class MyModel
{
    public int StatusID { get; set; }
}

Controller:

public class HomeController : Controller
{
    public ActionResult Index()
    {
        // TODO: obviously this comes from your DB,
        // but I hate showing code on SO that people are
        // not able to compile and play with because it has 
        // gazzilion of external dependencies
        var statuses = new SelectList(
            new[] 
            {
                new { ID = 1, Name = "status 1" },
                new { ID = 2, Name = "status 2" },
                new { ID = 3, Name = "status 3" },
                new { ID = 4, Name = "status 4" },
            }, 
            "ID", 
            "Name"
        );
        ViewBag.Statuses = statuses;

        var model = new MyModel();
        model.StatusID = 3; // preselect the element with ID=3 in the list
        return View(model);
    }
}

View:

@model MyModel
...    
@Html.DropDownListFor(model => model.StatusID, (SelectList)ViewBag.Statuses)

and here’s the correct way, using real view model:

Model

public class MyModel
{
    public int StatusID { get; set; }
    public IEnumerable<SelectListItem> Statuses { get; set; }
}

Controller:

public class HomeController : Controller
{
    public ActionResult Index()
    {
        // TODO: obviously this comes from your DB,
        // but I hate showing code on SO that people are
        // not able to compile and play with because it has 
        // gazzilion of external dependencies
        var statuses = new SelectList(
            new[] 
            {
                new { ID = 1, Name = "status 1" },
                new { ID = 2, Name = "status 2" },
                new { ID = 3, Name = "status 3" },
                new { ID = 4, Name = "status 4" },
            }, 
            "ID", 
            "Name"
        );
        var model = new MyModel();
        model.Statuses = statuses;
        model.StatusID = 3; // preselect the element with ID=3 in the list
        return View(model);
    }
}

View:

@model MyModel
...    
@Html.DropDownListFor(model => model.StatusID, Model.Statuses)

More Related Contents:

  1. Polymorphic model binding
  2. How do I specify different Layouts in the ASP.NET MVC 3 razor ViewStart file?
  3. ASP.NET MVC 3 – Partial vs Display Template vs Editor Template
  4. In MVC3 Razor, how do I get the html of a rendered view inside an action?
  5. How do you share scripts among multiple projects in one solution?
  6. Dependency Injection with Ninject and Filter attribute for asp.net mvc
  7. MVC 3 Model Binding a Sub Type (Abstract Class or Interface)
  8. Razor-based view doesn’t see referenced assemblies
  9. HTML.ActionLink vs Url.Action in ASP.NET Razor
  10. ASP.NET: This method cannot be called during the application’s pre-start initialization stage
  11. Using System.ComponentModel.DataAnnotations with Entity Framework 4.0
  12. Differences between Html.TextboxFor and Html.EditorFor in MVC and Razor
  13. How to change ‘data-val-number’ message validation in MVC while it is generated by @Html helper
  14. ASP.NET MVC3 and Windows Auth on IIS keeps redirecting to /Account/Login
  15. Fill drop down list on selection of another drop down list [closed]
  16. pass enum to html.radiobuttonfor MVC3
  17. Best place to set CurrentCulture for multilingual ASP.NET MVC web applications
  18. ASP.NET MVC – Authenticate users against Active Directory, but require username and password to be inputted
  19. asp.net mvc keep object alive, information
  20. MVC 3 file upload and model binding
  21. ASP.net MVC – Display Template for a collection
  22. How can I use Html.Action?
  23. Implementing “Remember Me” Feature in ASP.NET MVC
  24. How to reuse Areas, Controllers, Views, Models, Routes in multiple apps or websites
  25. Redirect to Action in another controller
  26. active menu item – asp.net mvc3 master page
  27. In what order are filters executed in asp.net mvc
  28. Html.DisplayFor not posting values to controller in ASP.NET MVC 3
  29. How do I create my own Scaffold Template in ASP.NET MVC 3?
  30. Load PartialView with using jquery Ajax?

Leave a Comment