When I open the view I have null object in model mvc

Question

Good news everyone. I have a little problem. I can't show the data in table. I moved code to HomeContoller and it's fixed bug with null object.

Home controller

using NarkomApp.Models;

using System.Collections.Generic; using System.Web.Mvc;

namespace NarkomApp.Controllers { public class HomeController : Controller { NarkomEntities dbModel = new NarkomEntities();

    public ActionResult Index()
    {
        return View();
    }

    public ActionResult PersonalPage()
    {
        PersonalPageModel personalPageModel = new PersonalPageModel();

        List<USERS> list_Users = new List<USERS>();
        List<PERSONAL_INF> list_PersonalInf = new List<PERSONAL_INF>();

        personalPageModel.list_Users = list_Users;
        personalPageModel.list_PersonalInf = list_PersonalInf;

        personalPageModel.ChangePasswordErrorMessage = "Новый пароль совпадает со старым!";

        return View("~/Views/Home/PersonalPage.cshtml", personalPageModel);
    }

    public ActionResult AddOrEdit()
    {
        return View();
    }

    public ActionResult LogOut()
    {
        int iIdUser = (int)Session["iIdUsers"];
        Session.Abandon();
        return RedirectToAction("Index", "Home");
    }

}

View code:

@model NarkomApp.Models.PersonalPageModel


@if (Model != null)
        {
            <table border="0">

                <tr>
                    <td colspan="2"><h2>Персональные данные</h2></td>
                    <td></td>
                </tr>

                @foreach (var personalInf in Model.list_PersonalInf)
                {
                    <tr>
                        <td><p>Город:</p></td>
                        <td>@Html.Label(@personalInf.vCity, new { htmlAttributes = new { @class = "form-control" } })</td>
                    </tr>
                    <tr>
                        <td><p>ФИО:</p></td>
                        <td>@Html.Label(@personalInf.vFIO, new { htmlAttributes = new { @class = "form-control" } })</td>
                    </tr>
                    <tr>
                        <td><p>Индекс:</p></td>
                        <td>@Html.Label(@personalInf.vIndex, new { htmlAttributes = new { @class = "form-control" } })</td>
                    </tr>
                    <tr>
                        <td><p>Населенный пункт:</p></td>
                        <td>@Html.Label(personalInf.vLocality, new { htmlAttributes = new { @class = "form-control" } })</td>
                    </tr>
                    <tr>
                        <td><p>Улица:</p></td>
                        <
                        <td>@Html.Label(@personalInf.vStreet, new { htmlAttributes = new { @class = "form-control" } })</td>
                    </tr>
                    <tr>
                        <td><p>Дом/корпус/строение:</p></td>
                        <td>@Html.Label(@personalInf.vHome, new { htmlAttributes = new { @class = "form-control" } })</td>
                    </tr>
                    <tr>
                        <td><p>Квартира:</p></td>
                        <
                        <td>@Html.Label(@personalInf.vApartment, new { htmlAttributes = new { @class = "form-control" } })</td>
                    </tr>
                    <tr>
                        <td><p>Телефон:</p></td>
                        <td>@Html.Label(@personalInf.vPhone, new { htmlAttributes = new { @class = "form-control" } })</td>
                    </tr>
                }

                <tr>
                    <td colspan="2"><hr /></td>
                    <td></td>
                </tr>

                <tr>
                    <td colspan="2"><h2>Форма изменения данных</h2></td>
                    <td></td>
                </tr>

                @foreach (var personalInf in Model.list_PersonalInf)
                {
                    <tr>
                        <td><p>Город:</p></td>
                        <td>@Html.Editor(@personalInf.vCity, new { htmlAttributes = new { @class = "form-control" } })</td>
                    </tr>
                    <tr>
                        <td><p>ФИО:</p></td>
                        <td>@Html.Editor(@personalInf.vFIO, new { htmlAttributes = new { @class = "form-control" } })</td>
                    </tr>
                    <tr>
                        <td><p>Индекс:</p></td>
                        <td>@Html.Editor(@personalInf.vIndex, new { htmlAttributes = new { @class = "form-control" } })</td>
                    </tr>
                    <tr>
                        <td><p>Населенный пункт:</p></td>
                        <td>@Html.Editor(personalInf.vLocality, new { htmlAttributes = new { @class = "form-control" } })</td>
                    </tr>
                    <tr>
                        <td><p>Улица:</p></td>
                        <
                        <td>@Html.Editor(@personalInf.vStreet, new { htmlAttributes = new { @class = "form-control" } })</td>
                    </tr>
                    <tr>
                        <td><p>Дом/корпус/строение:</p></td>
                        <td>@Html.Editor(@personalInf.vHome, new { htmlAttributes = new { @class = "form-control" } })</td>
                    </tr>
                    <tr>
                        <td><p>Квартира:</p></td>
                        <
                        <td>@Html.Editor(@personalInf.vApartment, new { htmlAttributes = new { @class = "form-control" } })</td>
                    </tr>
                    <tr>
                        <td><p>Телефон:</p></td>
                        <td>@Html.Editor(@personalInf.vPhone, new { htmlAttributes = new { @class = "form-control" } })</td>
                    </tr>


                    <tr>
                        <td><input type="submit" value="Изменить" class="btn-submit" /></td>
                        <td><input type="reset" value="Очистка" class="btn-submit" /></td>
                    </tr>

                }


                <tr>
                    <td colspan="2"><hr /></td>
                    <td></td>
                </tr>

                <tr>
                    <td colspan="2"><h2>Форма изменения пароля</h2></td>
                    <td></td>
                </tr>

                @foreach (var users in Model.list_Users)
                {
                    <tr>
                        <td><p>Старый пароль:</p></td>
                        <td>
                            @Html.Editor(Model.NewPassword, new { htmlAttributes = new { @class = "form-control" } })<br />
                            @Html.ValidationMessage(Model.NewPassword, "", new { @class = "text-danger" })
                        </td>
                    </tr>

                    <tr>
                        <td><p>Новый пароль:</p></td>
                        <td>
                            @Html.Editor(@users.vPassword, new { htmlAttributes = new { @class = "form-control" } })<br />
                            @Html.ValidationMessage(@users.vPassword, "", new { @class = "text-danger" })
                        </td>
                    </tr>

                    <tr>
                        <td><p>Подтвердите пароль:</p></td>
                        <td>
                            @Html.Editor(@users.ConfirmPassword, new { htmlAttributes = new { @class = "form-control" } })<br />
                            @Html.ValidationMessage(@users.ConfirmPassword, "", new { @class = "text-danger" })
                        </td>
                    </tr>
                }


                <tr>
                    <td><input type="submit" value="Изменить" class="btn-submit" /></td>
                    <td><input type="reset" value="Очистка" class="btn-submit" /></td>
                </tr>

                <tr>
                    <td colspan="2"><hr /></td>
                    <td></td>
                </tr>

                <tr>
                    <td colspan="2"><p>Подписаться на рассылку</p> @Html.CheckBox("cbIsSendInf", true)</td>
                    <td></td>
                </tr>

                <tr>
                    <td colspan="2"><hr /></td>
                    <td></td>
                </tr>

                <tr>
                    <td colspan="2">@Html.ActionLink("Выход из аккаунта!", "LogOut", "Home", null, new { @class = "form-control" })</td>
                    <td></td>
                </tr>

            </table>

        } @* End if *@
        else
        {
            <h2>Проблема с сессией, пустой объект!</h2>
        }

Answer 1

Try and put PersonalPageModel personalPageModel = new PersonalPageModel(); inside your ActionResult or if you want it outside then try specifying public or private for your model. I hope that helps!

P.S. Run in Debug mode and put a breakpoint just before you return. Inspect your variables and see what is being held in them, I hope this helps you out to narrow down your problem!

Answer 2

I think its better to return just a new PersonalPageModel than just editing it every action. Keep in mind that every one controller in any web application are stateless - so you will not have the same object in another request (ofc you can have static object, but I think it isnt good to use static model in this situation)

I think this should solve your situation:

  return View("~/Views/Home/PersonalPage.cshtml", new PersonalPageModel(){ 
            ChangePasswordErrorMessage = "Новый пароль совпадает со старым!",
            list_Users  = new List<USERS>(),
            list_PersonalInf  = new List<PERSONAL_INF>()
  });

Right now in your case in every request you create a new object of PersonalPageModel which isnt good I think.

Answer 3

Create an instance of your View Model in the Action Method rather like below:

//PersonalPageModel personalPageModel = new PersonalPageModel();---> remove this

    // GET: PersonalPage
    public ActionResult PersonalPage()
    {
        PersonalPageModel personalPageModel = new PersonalPageModel(); // use here in the action method instead
        List<USERS> list_Users = new List<USERS>();
        List<PERSONAL_INF> list_PersonalInf = new List<PERSONAL_INF>();

        personalPageModel.list_Users = list_Users;
        personalPageModel.list_PersonalInf = list_PersonalInf;

        personalPageModel.ChangePasswordErrorMessage = "Новый пароль совпадает со старым!";

        return View("~/Views/Home/PersonalPage.cshtml", personalPageModel);
    }

Don't instantiate it in the Controller like you were doing before, it can expose it unplanned modifications and it's not the best as Chris Pratt pointed out.