formcollection only holds the selected html.listbox items values? MVC

Question

My scenario is this: I have two listbox\'s, one that contains all my database items, and an empty one. The user adds the items needed from the full listbox to the empty list

Answer 1

Why not have the list of items in checkboxes. Then you could iterate through the checkboxes in your action and grab all selected checkboxes.

<% foreach(var item in Model.Items) { %>

   <%= Html.CheckBox(String.Format("ItemID.{0}", item.ID)) %> // each item tagged by the items id

<% } %>

public ActionResult MyAction(FormCollection formCollection)
{

            foreach (var key in collection.AllKeys.Where(k => !k.Contains("SubmitButton")).ToArray<string>())
            {
                 // iterates thru check boxes we got rid of the button 

            }
}

Answer 2

Because it's just selectbox. You cannot post all values in selectbox. You have to use javascript to catch added items and store them in hidden input.

Un-tested code, but i think it help you.

<script type="text/javascript">
    function addItem() {
        var allItems = document.getElementById("AllItems");
        var op = allItems.options[allItems.selectedIndex];
        var hdSelectedItems = document.getElementById("hdSelectedItems");
        var lbSelectedItems = document.getElementById("lbSelectedItems");

        lbSelectedItems.options[lbSelectedItems.options.length] = op;

        if (hdSelectedItems.value != '') {
             hdSelectedItems.value += ","
        }
        hdSelectedItems.value += op.value;
    }
</script>
<%= Html.Hidden("hdSelectedItems") %>
<%= Html.ListBox("AllItems", Model.Items)%>
<%= Html.ListBox("lbSelectedItems") %>
<a href="#" onclick="addItem(); return false;">Add</a>

Answer 3

I am doing this as well, I think the way I solved it is a bit more elegant. Essentially I just have a Jquery function that runs before the form post that selects all the options.

    $(function () {
        $("form").submit(function (e) {
            $("#box2View option").attr("selected", "selected");
        });
    });