POST操作后，复杂模型为空

Question

There are a lot of posts about this problem but I still can't find the correct solution. Currently my model, view and controller look like this:

View:

@model Pro.Web.Models.CatDetailsView

@using (Html.BeginForm("Details", "Cat", Model, FormMethod.Post))
{
@Html.AntiForgeryToken()
@Html.ValidationSummary()

<h2>Details</h2>

<ol>
    <li>
        @Html.LabelFor(model => model.Cat.Name)
        <p>@Html.DisplayFor(model => model.Cat.Name, new { @readonly = "true" })</p>
    </li>

    <li>
        @Html.LabelFor(model => model.Cat.Owner)
        <p>@Html.DisplayFor(model => model.Cat.Owner.UserName, new { @readonly = "true" })</p>
    </li>

    <li>
        @Html.LabelFor(model => model.Cat.BornDate)
        <p>@Html.DisplayFor(model => model.Cat.BornDate, new { @readonly = "true" })</p>
    </li>

    <li>
        @Html.LabelFor(model => model.Cat.Age)
        <p>@Html.DisplayFor(model => model.Cat.Age, new { @readonly = "true" })</p>
    </li>


    <li>
        @Html.LabelFor(model => model.Cat.CatColorValue)
        <p>@Html.DisplayEnumFor(model => model.Cat.CatColorValue, typeof(Pro.Web.Models.Entities.Enums.CatColor))</p>
    </li>

    <li>
        @Html.LabelFor(model => model.Cat.Description)
        <p>@Html.DisplayFor(model => model.Cat.Description, new { @readonly = "true" })</p>
    </li>

</ol>

<input type="submit" value="Edit details" name="Command" />

}

Model:

public class CatDetailsView
{
    public Cat Cat { get; set; }
}

Controller:

[HttpPost]
    public ActionResult Details(CatDetailsView model, string Command)
    {
        if (Command.Equals("Edit details"))
        {
            Cat cat = this._catRepository.Find(model.Cat.Id);
            if (cat != null)
            {
                return RedirectToAction("Edit", "Cats", new { id = cat.Id });
            }
            else
            {
                return View(model);
            }
        }

        else
        {
            return View(model);
        }

    }

The problem is that controller always receives null for model. I'm looking in that code and can't see what is wrong. I've just began learning so I am probably missing something trivial. I hope someone has an idea what could be a problem.

Thank you.

Answer 1

You are using DisplayFor instead of EditorFor, so you're not going to be submitting anything.

DisplayFor is used to display data.

EditorFor is used to add form input elements such as text boxes, radio buttons, check boxes, etc.

edit
sormii mentioned this in the comments so I will add it to the answer. If you want the user to be able to change the values that are getting posted, then you should use EditorFor, but if you want to just show them the data (not allow them to change) then you can use HiddenFor right after each DisplayFor. This will put a hidden input that will get posted.

It looks like you are trying to use readonly=true, so I think you might want to use TextBoxFor in order to do that.