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])
}