MVC 3 - Why am I not getting checkbox values in FormCollection?

Question

I have 12 checkboxes in my View and when I select some of the items and press the submit button the formcollection only has two keys [0] "IsSelected" and [1] "Playlists".

Here is my View. It is not strongly typed to a model and it is a partial view.

@using (Html.BeginForm()) {
<p>Tracks</p>
    foreach (Sem_App.Models.Track track in ViewBag.Tracks)
    {
        @Html.CheckBoxFor(m => track.IsSelected)
        @track.Title
    }
            @Html.DropDownList("Playlists", String.Empty)
            <input type="submit" value="Add To Playlist" />
}

Controller

    [HttpPost]
    public ActionResult Search(String criteria, FormCollection collection)
    {

    }

Is there any way I can fix that? or is there a better way to pass the updated ViewBag.Tracks list to the controller? as I have a bool IsSelected Field for each track

Answer 1

The checkbox form items need unique name/id properties to come through correctly as a list in the POST ActionResult. Most of the examples I have seen use an index property to assign names of the input elements like so:

@using (Html.BeginForm()) {
<p>Tracks</p>
    int index = 0;
    foreach (Stackoverflow.Controllers.Track track in ViewBag.Tracks)
    {
        @Html.CheckBox("tracks[" + index + "].IsSelected", track.IsSelected)
        @Html.Hidden("tracks[" + index + "].Title", track.Title)
        @track.Title
        index++;
    }

    @Html.DropDownList("Playlists", String.Empty)
    <input type="submit" value="Add To Playlist" />
}

Then it would come through on POST method like this:

[HttpPost]
public ActionResult Search(String criteria, string PlayLists, List<Track> tracks)
{

}