Bootstrap Multiselect Get Selected values on HttpP

Question

I'm using this Bootstrap Multiselect and my problem is that I cant get the selected values on HttpPost on ASP.Net MVC.

Problems Encountered:

• after clicking save, Only the first selected value is the present on the model. (SOLVED)

• after clicking save, Only the first selected value is the present on the dropdownlist.

Sample.chtml:

@model SampleProject.Models.SampleViewModel

@using (Html.BeginForm())
{
    @Html.DropDownListFor(model => model.Selected, new SelectList(Model.List, "value", "text"), new { @class = "multiselect form-control", multiple = "multiple" })
    <input type="submit" value="Save" />
}

Model:

public class SampleViewModel
{
    public string[] Selected { get; set; }
    public SelectList List { get; set; }
}

Controller:

public class DashboardController : Controller
{
    public ActionResult Sample()
    {
        SampleViewModel model = new SampleViewModel();
        model.List = new SelectList(new List<string>() { "1", "2", "3" });

        return View(model);
    }

    [HttpPost]
    public ActionResult Sample(SampleViewModel model)
    {
        model.List = new SelectList(new List<string>() { "1", "2", "3" });

        return View(model);
    }
}

Selection:

I cant get the selected values correctly on HttpPost

Code Behind/HttpPost: (Wrong)

After HttpPost: (Correct)

Answer 1

Didn't see this answer anywhere, so to solve the issue with having only 1 item selected after the post back you need to use:

@Html.ListBoxFor(.. 
instead of @Html.DropDownListFor

Answer 2

A <select multiple="multiple"> posts back an array of values (not a single value). You property Selected needs to be IEnumerable, for example

public string[] Selected { get; set; }

Side note: Since the text and value properties are the same, you can simplify you code by making the List property SelectList

public SelectList List { get; set; }

and then in the controller

model.List = new SelectList(new List<string>() { "1", "2", "3" })

(although its not clear why you would not use int)