Value of Foreach Loop does not pass to the HttpPost controller action model

Question

User210895818 posted

Hi I have separated the list of students based on their department then try to edit their all students of the same DEPARTMENT on a one-click button but when i tried to pass data from foreach loop to the controller data does not pass to the model.

Here is my controller:

        public ActionResult AllotRegistration()
        {
            StudentSearchModel depart = new StudentSearchModel();

            ViewBag.DepartmentList = Context.Departments.Where(a=>a.Description == "Academic").ToList();

            List<StdListModel> model = new List<StdListModel>();
            var query = (from e in Context.StdEnrollments
                         join d in Context.StdDetails on e.StdReg_ref_id equals d.ID
                         join s in Context.DegreePrograms on e.DegreeProgram_ref_id equals s.ID
                       //  where e.Depart_ref_id == value.Depart_ref_id
                         where s.StartYear == "2019" && e.Program_ref_id == 1 && e.Status == "Active"
                          
                         select new StdListModel
                         {
                             ID = e.ID,
                             Registration =e.Resgistration                             
                         }).ToList();
            foreach (var item in query)
            {
                model.Add(new StdListModel()
                {
                    ID = item.ID,
                    Registration = item.Registration
                });
            }
            return View(model);
        }

        [HttpPost]
        public ActionResult AllotRegistration(List<StdListModel> model)
        {
            ViewBag.DepartmentList = Context.Departments.Where(a => a.Description == "Academic").ToList();
            foreach (var i in model)
            {
                var c = Context.StdEnrollments.Where(a => a.ID.Equals(i.ID)).FirstOrDefault();
                c.Resgistration = i.Registration;
            }
            Context.SaveChanges();
            return View(model);
        }

and my View is as:

@model List<project.Models.StdListModel>

@{
    ViewBag.Title = "AppliedStdDetail";
    ViewBag.Module = "Department";
    ViewBag.Screen = "AppliedStudents";
    ViewBag.MenuID = "submun_studentDetails";
    Layout = "~/Views/Shared/_SRSLayout.cshtml";
}
<div class="page-content">
    <div class="page-header">
        <h1>
            Student Registration Panel
        </h1>
    </div>
    <div class="col-xs-10">

        <div class="panel-group" id="accordion">
            @{ int j = 0; }
            @foreach (var item in @ViewBag.DepartmentList)
        {
                <div class="panel panel-default" style="margin-top:5px;">
                    <div class="panel-heading" style="background-color:cornflowerblue;">
                        <h4 class="panel-title">
                            <a data-toggle="collapse" data-parent="#accordion" href="#collapse-@j" aria-expanded="false" style="color:white">
                                @item.DepartName
                            </a>
                        </h4>
                    </div>
                    <div id="collapse-@j" class="panel-collapse collapse">
                        <div class="panel-body">
                            @using (Html.BeginForm("AllotRegistration", "Student", FormMethod.Post))
                        {
                                <table id="dynamic-table" class="table table-striped table-bordered table-hover" name="StudentDetail">
                                    <thead>
                                        <tr>
                                            @*<th>Actions</th>*@
                                            <th>Registration</th>
                                        </tr>
                                    </thead>
                                    <tbody>
                                     @foreach (var i in Model.Where(s => s.Depart_ref_id == item.ID).ToList())
                                     {
                                        <tr>
                                            <input type="hidden" name="ID" value="@i.ID" />
                                            <td>
                                                @if (i.Registration != "0")
                                                {
                                                    @Html.DisplayFor(model => i.Registration)
                                                }
                                                else
                                                {
                                                    <input name="Registration" value="@i.Registration" />
                                                    @*@Html.EditorFor(model => i.Registration)*@
                                                }
</td>
                                        </tr>

                                     }
                                    </tbody>
                                </table>
                                <p>
                                    <input type="submit" value="Submit" />
                                </p>
                        }
                        </div>
                    </div>
                </div>
            j++;
        }

        </div>

    </div>

</div>

Answer 1

User475983607 posted

The input names must be indexed for the model binder to populate the collection.

https://haacked.com/archive/2010/07/16/uploading-files-with-aspnetmvc.aspx/

Answer 2

User210895818 posted

Hi Mgebhard thank for your reply but I need to do this with foreach loop because with for loop condition where clause does not work

@for (int i = 0; i < Model.Where(a=>a.Depart_ref_id == item.ID)).Count(); i++)

Answer 3

User665608656 posted

Hi Ridzi,

According to your description, after you use for loop to fill table data, you also need to add a hidden control to store value which displays as label not textbox.

Text tags don't pass values when you submit a form, but you can pass them by adding hidden controls, you can refer to this link : https://stackoverflow.com/a/44628875

Here is the code:

                                        @for (int i = 0; i < Model.Where(s => s.Depart_ref_id == item.ID).ToList().Count; i++)
                                        {
                                            <tr>
                                                @Html.HiddenFor(model => Model[i].ID) 
                                                <td>
                                                    @if (Model[i].Registration != "0")
                                                    {
                                                        @Html.DisplayFor(model => Model[i].Registration)
                                                        @Html.HiddenFor(model => Model[i].Registration) 
                                                    }
                                                    else
                                                    { 
                                                        @Html.EditorFor(model => Model[i].Registration) 
                                                    }
                                                </td>
                                            </tr>
                                        }

Best Regards,

YongQing.

Answer 4

User210895818 posted

Yongqing Yu

after you use for loop to fill table data,

Thanks, Yongqing for your reply, but I can't use for loop because on a condition "where" clause does not work. Can you please guide me with foreach loop or why where clause is not working in for loop?

Answer 5

User665608656 posted

Hi Ridzi,

Thanks, Yongqing for your reply, but I can't use for loop because on a condition "where" clause does not work. Can you please guide me with foreach loop or why where clause is not working in for loop?

I'm very sorry that I didn't notice this issue. After some tests, I suggest that you can prevent submit form events, and then complete these operations in jquery's ajax.

<script src="~/Scripts/jquery-3.3.1.js"></script>
<script type="text/javascript">
    $(function () {
        $("input[type='submit']").click(function () {
            event.preventDefault();
            var table = $(this).parent("p").prev("table");
            var idlist = [];
            var namelist = [];
            // use loop to find fields you need to pass
            for (var i = 0; i < table.find("input").length; i++) {
                if (table.find("input")[i].name.includes("ID")) {
                    idlist.push(table.find("input")[i].value);
                }
                if (table.find("input")[i].name.includes("Registration")) {
                    namelist.push(table.find("input")[i].value);
                }
            }
            var model = [];
            for (var i = 0; i < idlist.length; i++) {
                model.push({ ID: idlist[i], Registration: namelist[i] });
            } 
            $.ajax({
                contentType: 'application/json; charset=utf-8',
                dataType: 'json',
                type: 'POST',
                url: '/Student/AllotRegistration',
                data: JSON.stringify({ 'model': model })
            });
        })
    })
</script>

And here is the code of bind data:

                                      @for (int i = 0; i < Model.Count; i++)
                                        {
                                            if (Model[i].Depart_ref_id == item.ID)
                                            {
                                                <tr>
                                                    @Html.HiddenFor(model => Model[i].ID ) 
                                                    <td>
                                                        @if (Model[i].Registration != "0")
                                                        {
                                                            @Html.DisplayFor(model => Model[i].Registration)
                                                            @Html.HiddenFor(model => Model[i].Registration)
                                                        }
                                                        else
                                                        {
                                                            @Html.EditorFor(model => Model[i].Registration)
                                                        }
                                                    </td>
                                                </tr>
                                            }

                                        }

Best Regards,

YongQing.

Answer 6

User210895818 posted

Hi Yongqing, thanks for your help