ASP.NET MVC DropDownListFor not selecting value from model

Question

I\'m using ASP.NET MVC 3, and just ran into a \'gotcha\' using the DropDownListFor HTML Helper.

I do this in my Controller:

ViewBag.Ship         


        

Answer 1

I was just hit by this limitation and figured out a simple workaround. Just defined extension method that internally generates SelectList with correct selected item.

public static class HtmlHelperExtensions
{
    public static MvcHtmlString DropDownListForEx(
       this HtmlHelper htmlHelper,
       Expression> expression,
       IEnumerable selectList,
       object htmlAttributes = null)
    {
        var selectedValue = expression.Compile().Invoke(htmlHelper.ViewData.Model);
        var selectListCopy = new SelectList(selectList.ToList(), nameof(SelectListItem.Value), nameof(SelectListItem.Text), selectedValue);

        return htmlHelper.DropDownListFor(expression, selectListCopy, htmlAttributes);
    }
}

The best thing is that this extension can be used the same way as original DropDownListFor:

@for(var i = 0; i < Model.Items.Count(); i++)
{
   @Html.DropDownListForEx(x => x.Items[i].CountryId, Model.AllCountries)
}