ASP.NET Core MVC和EF Core 1.1

Question

I have question in regarding how to add parameter see my codes below:

[HttpPost]
    [ValidateAntiForgeryToken]
    public IActionResult Edit(Employee emp)
    {
        try
        {

            Employee updateEmp = _Context.Employee.FirstOrDefault(c => c.Idemployee == emp.Idemployee);
            updateEmp.Address = emp.Address;
            updateEmp.Age = emp.Age;
            updateEmp.ContactNumber = emp.ContactNumber;
            updateEmp.FullName = emp.FullName;
            updateEmp.Gender = emp.Gender;
            updateEmp.IsActive = emp.IsActive;

            _Context.Employee.Update(updateEmp);
            _Context.SaveChanges();

            return RedirectToAction("Index");
        }
        catch (Exception)
        {

            throw;
        }
    }

What I am trying to do here is I am trying to extract the emp.Idemployee from the querystring but it couldn't and redirect me to the error null exception.

I am using a model to extract the details form the cshtml.

public IActionResult Edit(int id)
    {
        var editEmployee = _Context.Employee.FirstOrDefault(c => c.Idemployee == id);

        return View(editEmployee);
    }

I don't know whats wrong with it but all of the other information are extracted except for Idemployee.

 @model Demo101.DAL.Entities.Models.Employee @{ ViewBag.Title = "Edit Employee"; } <h2>@ViewData["Title"]</h2> <form asp-controller="Employee" asp-action="Edit" method="post" class="form-horizontal" role="form"> <div class="form-horizontal"> <div asp-validation-summary="All" class="text-danger"></div> <!--FullName--> <label asp-for="Idemployee" class="col-md-2 control-label"></label> <div class="col-md-10"> @Html.LabelFor(model => model.Idemployee, new { @class = "form-control" }) @Html.ValidationMessageFor(model => model.Idemployee) </div> <!--FullName--> <label asp-for="FullName" class="col-md-2 control-label"></label> <div class="col-md-10"> @Html.TextBoxFor(model => model.FullName, new { @class = "form-control" }) @Html.ValidationMessageFor(model => model.FullName) </div> <!--Age--> <label asp-for="Age" class="col-md-2 control-label"></label> <div class="col-md-10"> @Html.TextBoxFor(model => model.Age, new { @class = "form-control" }) @Html.ValidationMessageFor(model => model.Age) </div> <!--ContactNumber--> <label asp-for="ContactNumber" class="col-md-2 control-label"></label> <div class="col-md-10"> @Html.TextBoxFor(model => model.ContactNumber, new { @class = "form-control" }) @Html.ValidationMessageFor(model => model.ContactNumber) </div> <!--Address--> <label asp-for="Address" class="col-md-2 control-label"></label> <div class="col-md-10"> @Html.TextBoxFor(model => model.Address, new { @class = "form-control" }) @Html.ValidationMessageFor(model => model.Address) </div> <!--Gender--> <label asp-for="Gender" class="col-md-2 control-label"></label> <div class="col-md-10"> @Html.TextBoxFor(model => model.Gender, new { @class = "form-control" }) @Html.ValidationMessageFor(model => model.Gender) </div> <!--IsActive--> <label asp-for="IsActive" class="col-md-2 control-label"></label> <div class="col-md-10"> @Html.CheckBoxFor(model => model.IsActive, new { @class = "form-control" }) @Html.ValidationMessageFor(model => model.IsActive) </div> <!--Create Button--> <div class="col-md-offset-2 col-md-10"> <input type="submit" value="Edit Employee" class="btn btn-default" /> </div> </div> </form> 

Thanks!

Answer 1

Look at my code below, give this a go

<!--IdEmployee-->
<label asp-for="Idemployee" class="col-md-2 control-label"></label>
<div class="col-md-10">
    @Html.LabelFor(model => model.Idemployee, new { @class = "form-control" })
    @Html.HiddenFor(model => model.Idemployee)
    @Html.ValidationMessageFor(model => model.Idemployee)
</div>

Answer 2

Your view does not contain any field with Employee value. You have label, you have validation message, but not value itself. Thus, you have no value in POST to server.

Add somewhere inside form:

@Html.HiddenFor(model => model.Idemployee)