MVC Html.DropDownListFor for simple list of strings, Model: IEnumerable>

Question

My issue: the dropdownlistfor is not selecting the correct value of string when loading the page. Here is the code and view:

Surcharges.html

@model IEnumerable<IEnumerable<string>>
@{
   ViewBag.Title = "Surcharge Management";
}
<div id="mainTitleDiv" class="mainTitle">
    <span style="display:inline-block;">@ViewBag.Title</span>
</div>
<br />
<table class="table">  
@{
    int i = 0;
    foreach (var surcharge in Model)
    {
        int j = 0;
        <tr>
            @foreach (var item in surcharge)
            {
                if (i == 0)
                {
                    @:<th>@Html.DisplayFor(model => item)</th>
                }
                else
                {
                    if (j == 0)
                    {
                        @:<th>@Html.DisplayFor(model => item)</th>
                    }
                    else
                    {
                        @:<td>
                        if (!string.IsNullOrEmpty(item) && (i == 2)) // Type
                        {
                            @Html.DropDownListFor(x => item, new List<SelectListItem>
                            {
                                new SelectListItem() {Text = "Fixed Amount", Value ="0"},
                                new SelectListItem() {Text = "Percentage",  Value ="1"}
                            }, new { style = "width:100%; height:34px;" } )
                        }
                        else
                        {
                            @Html.EditorFor(model => item, new { htmlAttributes = new { @class = "form-control" } })
                            @Html.ValidationMessageFor(model => item, "", new { @class = "text-danger" })
                        }
                        @:</td>
                    }
                    j++;
                }
            }
        </tr>
        i++;
    }
}

AdminController.cs

public ActionResult Surcharges()
{
    if (!User.Identity.IsAuthenticated)
    {
        return RedirectToAction("Login", "Account");
    }

    int userId = User.Identity.GetUserId<int>();
    var query = db.Surcharges.Where(x => x.UserId == userId).OrderBy(x => x.Id).ToList();
    IEnumerable<IEnumerable<string>> surcharges = Utility.Pivot<string>(Utility.GetSurchargeList(query));            

    return View(surcharges);
}

Surcharges page Surcharge

S2 and D1 have the string value "1" and not selected by the dropdownlist.

What am I doing wrong ?
Do I need a model to post the data edited back to the server ?
What should the correct model look like ?

Thanks

You cannot use a `foreach` loop to generate form controls for a collection - binding does not work (refer [Post an HTML Table to ADO.NET DataTable](https://stackoverflow.com/questions/30094047/post-an-html-table-to-ado-net-datatable/30094943#30094943) — , Sep 22 '17 at 00:42
You also need to refer [MVC5 - How to set “selectedValue” in DropDownListFor Html helper](https://stackoverflow.com/questions/41719293/mvc5-how-to-set-selectedvalue-in-dropdownlistfor-html-helper/41731685#41731685) for dealing with a dropdownlist in a loop — , Sep 22 '17 at 00:43

score 0 · Answer 1 · answered Sep 22 '17 at 13:59

Thanks, Stephen. My ASP.NET MVC project requirement is to design a page that looks like this image:

Surcharge Page

and my Surcharge table and data look like this:

Surcharge Table

What is your suggestion regarding the model that properly works and binds to the table ?

Is it better to use a grid with Edit and Delete buttons instead of the foreach table ?

I'm looking for the best model that actually allows each row to be edited and saved into the table (dropdownlist for the Type field).

MVC Html.DropDownListFor for simple list of strings, Model: IEnumerable>

1 Answers1