Get Value of Property (List<long>) in Post Action in ASP.NET MVC3 - asp.net-mvc

Question

This is My model:
public class MyModel
{
public List<long> NeededIds { get; set; }
public string Name { get; set; }
}
My Controllers:
public ActionResult Create()
{
MyModel model = new MyModel();
model.NeededIds = new List<long> { 1, 2, 3, 4 };
return View(model);
}
[HttpPost]
public ActionResult Create(MyModel model)
{
string name = model.Name;
List<long> ids = model.NeededIds;
return RedirectToAction("Index");
}
And View:
#model TestMVC.Models.MyModel
#using(Html.BeginForm()) {
<table>
<thead>
<tr>
<th>
Id
</th>
</tr>
</thead>
<tbody>
#foreach(long id in Model.NeededIds) {
<tr>
<td>
#id
</td>
</tr>
}
</tbody>
</table>
#Html.ValidationSummary(true)
<fieldset>
<legend>MyModel</legend>
<div class="editor-label">
#Html.LabelFor(model => model.Name)
</div>
<div class="editor-field">
#Html.EditorFor(model => model.Name)
#Html.ValidationMessageFor(model => model.Name)
</div>
<p>
<input type="submit" value="Create" />
</p>
</fieldset>
}
I set NeededIds in Get action and in the view I can see NeededIds. I also need it in Post action, but in post action the NeededIds is always null. How can I get the property value in post action when I set it in get action? What is your suggestion?

Answer 1

You are not posting your NeededIds back to the server. In order to get this working you can add them as hidden fields in a for loop inside the form:
#for (int i = 0; i < Model.NeededIds.Count(); i++) {
#Html.HiddenFor(model => model.NeededIds[i])
}

Answer 2

if you are using layout page than simply remove the form tag from the layout page.

Answer 3

in addition to the answer by Yakimych
you have kept the ids as constant.. this means two things
1. you can use arrays in place of list
2.you can just save the ids list/array in TempData and retrive it back from there when POST happens
you can do this like this
in your GET handler
TempData.Add("ids",idArray);
in your POST handler
var idArray = (long[])TempData["ids"];