kptailor1613 says:

how to edit value that we inserted

 Please explain in details.

What value you are inserting and what you want to edit.

i insert country aftr that state and city and that inserted value i want in edit view dropdown

Please share your controller and View.

This is my controller ode :

namespace VCS_MVC_project.Controllers
{
    public class StudentsController : Controller
    {
        private VCSContext db = new VCSContext();

        // GET: Students
        public ActionResult Index()
        {
            var students = db.Students.Include(s => s.City);
            return View(students.ToList());
        }

        // GET: Students/Details/5
        public ActionResult Details(int? id)
        {
            if (id == null)
            {
                return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
            }
            Student student = db.Students.Find(id);
            if (student == null)
            {
                return HttpNotFound();
            }
            return View(student);
        }

        // GET: Students/Create
        public ActionResult Create()
        {
            ViewBag.Countries = db.Countries;
            return View();
        }

        public JsonResult AjaxMethod(string type, int value)
        {
            switch (type)
            {
                case "ddlCountries":
                    var States = (from State in this.db.States
                                  where State.CountryID == value
                                  select new SelectListItem
                                  {
                                      Value = State.ID.ToString(),
                                      Text = State.StateName
                                  }).ToList();
                    return Json(States, JsonRequestBehavior.AllowGet);

                case "ddlStates":
                    var Cities = (from City in this.db.Cities
                                  where City.StateId == value
                                  select new SelectListItem
                                  {
                                      Value = City.ID.ToString(),
                                      Text = City.CityName
                                  }).ToList();
                    return Json(Cities, JsonRequestBehavior.AllowGet);

            }
            return null;
        }

        // POST: Students/Create
        // To protect from overposting attacks, enable the specific properties you want to bind to, for
        // more details see https://go.microsoft.com/fwlink/?LinkId=317598.
        [HttpPost]
        [ValidateAntiForgeryToken]
        public ActionResult Create([Bind(Include = "ID,Name,Dob,EmailID,Password,PhoneNO,Image,CityId,ZipCode,Address,Gender")] Student student, HttpPostedFileBase image)
        {
            try
            {
                if (ModelState.IsValid)
                {
                    string hashedPassword = BCrypt.Net.BCrypt.HashPassword(student.Password);
                    student.Password = hashedPassword;
                    var filename = Path.GetFileName(image.FileName);
                    var path = Path.Combine(Server.MapPath("~/S_Images/" + image.FileName));
                    image.SaveAs(path);
                    student.Image = filename;
                    db.Students.Add(student);
                    db.SaveChanges();
                    return RedirectToAction("Index");
                }

                ViewBag.CityId = new SelectList(db.Cities, "ID", "CityName", student.CityId);
                return View(student);
            }
            catch (Exception ex)
            {
                return RedirectToAction("Index", "Error");
            }

        }

        // GET: Students/Edit/5
        public ActionResult Edit(int? id)
        {
            if (id == null)
            {
                return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
            }
            Student student = db.Students.Find(id);
            ViewBag.Countries = db.Countries;
            //ViewBag.States = db.States;
            if (student == null)
            {
                return HttpNotFound();
            }
            //ViewBag.CountryId = new SelectList(db.Countries, "ID", "CountryName", student.CityId.State.CountryID);
            //ViewBag.StateId = new SelectList(db.Cities, "ID", "StateName", student.City.StateId);
            ViewBag.CityId = new SelectList(db.Cities, "ID", "CityName", student.CityId);
            return View(student);
        }

        // POST: Students/Edit/5
        // To protect from overposting attacks, enable the specific properties you want to bind to, for
        // more details see https://go.microsoft.com/fwlink/?LinkId=317598.
        [HttpPost]
        [ValidateAntiForgeryToken]
        public ActionResult Edit([Bind(Include = "ID,Name,Dob,EmailID,Password,PhoneNO,Image,CityId,ZipCode,Address,Gender")] Student student)
        {
            if (ModelState.IsValid)
            {
                string hashedPassword = BCrypt.Net.BCrypt.HashPassword(student.Password);
                student.Password = hashedPassword;
                db.Entry(student).State = EntityState.Modified;
                db.SaveChanges();
                return RedirectToAction("Index");
            }
            ViewBag.CountryId = new SelectList(db.Countries, "ID", "CountryName", student.City.State.CountryID);
            ViewBag.StateId = new SelectList(db.Cities, "ID", "StateName", student.City.StateId);
            ViewBag.CityId = new SelectList(db.Cities, "ID", "CityName", student.CityId);
            return View(student);
        }

        // GET: Students/Delete/5
        public ActionResult Delete(int? id)
        {
            if (id == null)
            {
                return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
            }
            Student student = db.Students.Find(id);
            if (student == null)
            {
                return HttpNotFound();
            }
            return View(student);
        }

        // POST: Students/Delete/5
        [HttpPost, ActionName("Delete")]
        [ValidateAntiForgeryToken]
        public ActionResult DeleteConfirmed(int id)
        {
            Student student = db.Students.Find(id);
            db.Students.Remove(student);
            db.SaveChanges();
            return RedirectToAction("Index");
        }

        protected override void Dispose(bool disposing)
        {
            if (disposing)
            {
                db.Dispose();
            }
            base.Dispose(disposing);
        }
    }
}

this is my view code :

Create :

@model VCS_MVC_project.Models.Student

@{
    ViewBag.Title = "Create";
    Layout = "~/Views/Shared/_Layout.cshtml";
}

<h2>Create</h2>

@using (Html.BeginForm("Create", "Students", FormMethod.Post, new { enctype = "multipart/form-data" }))
{
    @Html.AntiForgeryToken()

    <div class="form-horizontal">
        <h4>Student</h4>
        <hr />
        @Html.ValidationSummary(true, "", new { @class = "text-danger" })
        <div class="form-group">
            @Html.LabelFor(model => model.Name, htmlAttributes: new { @class = "control-label col-md-2" })
            <div class="col-md-10">
                @Html.TextBoxFor(model => model.Name, new { @class = "form-control" })
                @Html.ValidationMessageFor(model => model.Name, "", new { @class = "text-danger" })
            </div>
        </div>

        <div class="form-group">
            @Html.LabelFor(model => model.Dob, htmlAttributes: new { @class = "control-label col-md-2" })
            <div class="col-md-10">
                @Html.TextBoxFor(model => model.Dob, new { @class = "form-control", type = "date" })
                @Html.ValidationMessageFor(model => model.Dob, "", new { @class = "text-danger" })
            </div>
        </div>

        <div class="form-group">
            @Html.LabelFor(model => model.EmailID, htmlAttributes: new { @class = "control-label col-md-2" })
            <div class="col-md-10">
                @Html.TextBoxFor(model => model.EmailID, new { @class = "form-control" })
                @Html.ValidationMessageFor(model => model.EmailID, "", new { @class = "text-danger" })
            </div>
        </div>

        <div class="form-group">
            @Html.LabelFor(model => model.Password, htmlAttributes: new { @class = "control-label col-md-2" })
            <div class="col-md-10">
                @Html.PasswordFor(model => model.Password, new { @class = "form-control" })
                @Html.ValidationMessageFor(model => model.Password, "", new { @class = "text-danger" })
            </div>
        </div>

        <div class="form-group">
            @Html.LabelFor(model => model.PhoneNO, htmlAttributes: new { @class = "control-label col-md-2" })
            <div class="col-md-10">
                @Html.TextBoxFor(model => model.PhoneNO, new { @class = "form-control" })
                @Html.ValidationMessageFor(model => model.PhoneNO, "", new { @class = "text-danger" })
            </div>
        </div>

        <div class="form-group">
            @Html.LabelFor(model => model.Image, htmlAttributes: new { @class = "control-label col-md-2" })
            <div class="col-md-10">

                @Html.TextBoxFor(model => model.Image, new { type = "file", @class = "form-control" })
                @Html.ValidationMessageFor(model => model.Image, "", new { @class = "text-danger" })
            </div>
        </div>

        <div class="form-group">
            @Html.LabelFor(model => model.Address, htmlAttributes: new { @class = "control-label col-md-2" })
            <div class="col-md-10">
                @Html.TextBoxFor(model => model.Address, new { @class = "form-control" })
                @Html.ValidationMessageFor(model => model.Address, "", new { @class = "text-danger" })
            </div>
        </div>

        <div class="form-group">
            @Html.LabelFor(model => model.Gender, htmlAttributes: new { @class = "control-label col-md-2" })
            <div class="col-md-10">
                @Html.RadioButtonFor(model => model.Gender, "Male")Male
                @Html.RadioButtonFor(model => model.Gender, "Female")Female
                @Html.ValidationMessageFor(model => model.Gender, "", new { @class = "text-danger" })
            </div>
        </div>

        <div class="form-group">
            @Html.LabelFor(model => model.City.State.Country, htmlAttributes: new { @class = "control-label col-md-2" })
            <div class="col-md-10">
                @Html.DropDownList("countryid", new SelectList(ViewBag.Countries, "ID", "CountryName"), "---Select Country---", new { @class = "form-control" })
            </div>
        </div>

        <div class="form-group">
            @Html.LabelFor(model => model.City.State, htmlAttributes: new { @class = "control-label col-md-2" })
            <div class="col-md-10">
                <select id="stateid" name="StateId" class="form-control">
                    <option value="">---Select State---</option>
                </select>
            </div>
        </div>

        <div class="form-group">
            @Html.LabelFor(model => model.City, htmlAttributes: new { @class = "control-label col-md-2" })
            <div class="col-md-10">
                <select id="cityid" name="CityId" class="form-control">
                    <option value="">---Select City---</option>
                </select>
            </div>
        </div>

        <div class="form-group">
            @Html.LabelFor(model => model.ZipCode, htmlAttributes: new { @class = "control-label col-md-2" })
            <div class="col-md-10">
                @Html.TextBoxFor(model => model.ZipCode, new { @class = "form-control" })
                @Html.ValidationMessageFor(model => model.ZipCode, "", new { @class = "text-danger" })
            </div>
        </div>


        <div class="form-group">
            <div class="col-md-offset-2 col-md-10">
                <input type="submit" value="Create" class="btn btn-default" />
            </div>
        </div>
    </div>
}

@section scripts {
    <script>

        $(function () {
            $("#countryid").change(function () {
                $.ajax({
                    url: "/Students/AjaxMethod",
                    type: "get",
                    contentType: 'application/json',
                    data: { type: "ddlCountries", value: $("#countryid").val() },
                    success: function (result) {
                        //$("#City_StateId").html(result);
                        var options = '';

                        for (var i = 0; i < result.length; i++) { // Loop through the data & construct the options
                            options += '<option value="' + result[i].Value + '">' + result[i].Text + '</option>';
                        }

                        // Append to the html
                        $('#stateid').append(options);
                    },
                    error: function (ex) {
                        alert(ex)
                    }
                });
            });
        });


        $(function () {
            $("#stateid").change(function () {
                $.ajax({
                    url: "/Students/AjaxMethod",
                    type: "get",
                    contentType: 'application/json',
                    data: { type: "ddlStates", value: $("#stateid").val() },
                    success: function (result) {
                        //$("#City_StateId").html(result);
                        var options = '';

                        for (var i = 0; i < result.length; i++) { // Loop through the data & construct the options
                            options += '<option value="' + result[i].Value + '">' + result[i].Text + '</option>';
                        }

                        // Append to the html
                        $('#cityid').append(options);
                    },
                    error: function (ex) {
                        alert(ex)
                    }
                });
            });
        });
    </script>
}

<div>
    @Html.ActionLink("Back to List", "Index")
</div>

Edit:

@model VCS_MVC_project.Models.Student

@{
    ViewBag.Title = "Edit";
}

<h2>Edit</h2>

@using (Html.BeginForm("Edit", "Students", FormMethod.Post, new { enctype = "multipart/form-data" }))
{
    @Html.AntiForgeryToken()

    <div class="form-horizontal">
        <h4>Student</h4>
        <hr />
        @Html.ValidationSummary(true, "", new { @class = "text-danger" })
        @Html.HiddenFor(model => model.ID)

        <div class="form-group">
            @Html.LabelFor(model => model.Name, htmlAttributes: new { @class = "control-label col-md-2" })
            <div class="col-md-10">
                @Html.EditorFor(model => model.Name, new { htmlAttributes = new { @class = "form-control" } })
                @Html.ValidationMessageFor(model => model.Name, "", new { @class = "text-danger" })
            </div>
        </div>

        <div class="form-group">
            @Html.LabelFor(model => model.Dob, htmlAttributes: new { @class = "control-label col-md-2" })
            <div class="col-md-10">
                @Html.TextBoxFor(model => model.Dob, new { @class = "form-control", type = "date" })
                @Html.ValidationMessageFor(model => model.Dob, "", new { @class = "text-danger" })
            </div>
        </div>

        <div class="form-group">
            @Html.LabelFor(model => model.EmailID, htmlAttributes: new { @class = "control-label col-md-2" })
            <div class="col-md-10">
                @Html.EditorFor(model => model.EmailID, new { htmlAttributes = new { @class = "form-control" } })
                @Html.ValidationMessageFor(model => model.EmailID, "", new { @class = "text-danger" })
            </div>
        </div>

        <div class="form-group">
            @Html.LabelFor(model => model.Password, htmlAttributes: new { @class = "control-label col-md-2" })
            <div class="col-md-10">
                @Html.EditorFor(model => model.Password, new { htmlAttributes = new { @class = "form-control" } })
                @Html.ValidationMessageFor(model => model.Password, "", new { @class = "text-danger" })
            </div>
        </div>

        <div class="form-group">
            @Html.LabelFor(model => model.PhoneNO, htmlAttributes: new { @class = "control-label col-md-2" })
            <div class="col-md-10">
                @Html.EditorFor(model => model.PhoneNO, new { htmlAttributes = new { @class = "form-control" } })
                @Html.ValidationMessageFor(model => model.PhoneNO, "", new { @class = "text-danger" })
            </div>
        </div>

        <div class="form-group">
            @Html.LabelFor(model => model.Image, htmlAttributes: new { @class = "control-label col-md-2" })
            <div class="col-md-10">
                @Html.TextBoxFor(model => model.Image, new { @class = "form-control", type = "file" })
                @Html.ValidationMessageFor(model => model.Image, "", new { @class = "text-danger" })
            </div>
        </div>

        <div class="form-group">
            @Html.LabelFor(model => model.Gender, htmlAttributes: new { @class = "control-label col-md-2" })
            <div class="col-md-10">
                @Html.EditorFor(model => model.Gender, new { htmlAttributes = new { @class = "form-control" } })
                @Html.ValidationMessageFor(model => model.Gender, "", new { @class = "text-danger" })
            </div>
        </div>

        <div class="form-group">
            @Html.LabelFor(model => model.Address, htmlAttributes: new { @class = "control-label col-md-2" })
            <div class="col-md-10">
                @Html.EditorFor(model => model.Address, new { htmlAttributes = new { @class = "form-control" } })
                @Html.ValidationMessageFor(model => model.Address, "", new { @class = "text-danger" })
            </div>
        </div>

        <div class="form-group">
            @Html.LabelFor(model => model.City.State.Country, htmlAttributes: new { @class = "control-label col-md-2" })
            <div class="col-md-10">
                @* @Html.DropDownList("CountryId",null, String.Empty, new { @class = "form-control" })*@
                @Html.DropDownList("CountryId", new SelectList(ViewBag.Countries, "ID", "CountryName"), "---Select Country---", new { @class = "form-control" })
            </div>
        </div>

        <div class="form-group">
            @Html.LabelFor(model => model.City.State, htmlAttributes: new { @class = "control-label col-md-2" })
            <div class="col-md-10">
                @*@Html.DropDownList("StateId",null ,String.Empty, new { @class = "form-control" })*@
                <select id="stateid" name="StateId" class="form-control">
                    <option value="StateId">---Select State---</option>
                </select>
            </div>
        </div>

        <div class="form-group">
            @Html.LabelFor(model => model.City, htmlAttributes: new { @class = "control-label col-md-2" })
            <div class="col-md-10">

                <select id="cityid" name="CityId" class="form-control">
                    <option value="CityId">---Select City---</option>
                </select>
            </div>
        </div>

        <div class="form-group">
            @Html.LabelFor(model => model.ZipCode, htmlAttributes: new { @class = "control-label col-md-2" })
            <div class="col-md-10">
                @Html.EditorFor(model => model.ZipCode, new { htmlAttributes = new { @class = "form-control" } })
                @Html.ValidationMessageFor(model => model.ZipCode, "", new { @class = "text-danger" })
            </div>
        </div>

        <div class="form-group">
            <div class="col-md-offset-2 col-md-10">
                <input type="submit" value="Save" class="btn btn-default" />
            </div>
        </div>
    </div>
}



@section scripts {
    <script>

        $(function () {
            $("#countryid").change(function () {
                $.ajax({
                    url: "/Students/AjaxMethod",
                    type: "get",
                    contentType: 'application/json',
                    data: { type: "ddlCountries", value: $("#countryid").val() },
                    success: function (result) {
                        //$("#City_StateId").html(result);
                        var options = '';

                        for (var i = 0; i < result.length; i++) { // Loop through the data & construct the options
                            options += '<option value="' + result[i].Value + '">' + result[i].Text + '</option>';
                        }

                        // Append to the html
                        $('#stateid').append(options);
                    },
                    error: function (ex) {
                        alert(ex)
                    }
                });
            });
        });


        $(function () {
            $("#stateid").change(function () {
                $.ajax({
                    url: "/Students/AjaxMethod",
                    type: "get",
                    contentType: 'application/json',
                    data: { type: "ddlStates", value: $("#stateid").val() },
                    success: function (result) {
                        //$("#City_StateId").html(result);
                        var options = '';

                        for (var i = 0; i < result.length; i++) { // Loop through the data & construct the options
                            options += '<option value="' + result[i].Value + '">' + result[i].Text + '</option>';
                        }

                        // Append to the html
                        $('#cityid').append(options);
                    },
                    error: function (ex) {
                        alert(ex)
                    }
                });
            });
        });
    </script>
}

<div>
    @Html.ActionLink("Back to List", "Index")
</div>

Index:

@model IEnumerable<VCS_MVC_project.Models.Student>

@{
    ViewBag.Title = "Index";
}

<h2>Index</h2>

<p>
    @Html.ActionLink("Create New", "Create")
</p>
<table class="table">
    <tr>

        <th>
            @Html.DisplayNameFor(model => model.Name)
        </th>
        <th>
            @Html.DisplayNameFor(model => model.Dob)
        </th>
        <th>
            @Html.DisplayNameFor(model => model.EmailID)
        </th>
        @*<th>
            @Html.DisplayNameFor(model => model.Password)
            </th>*@
        <th>
            @Html.DisplayNameFor(model => model.PhoneNO)
        </th>
        <th>
            @Html.DisplayNameFor(model => model.Image)
        </th>
        <th>
            @Html.DisplayNameFor(model => model.Gender)
        </th>
        <th>
            @Html.DisplayNameFor(model => model.Address)
        </th>
        <th>
            @Html.DisplayNameFor(model => model.City.CityName)
        </th>
        <th>
            @Html.DisplayNameFor(model => model.ZipCode)
        </th>
        <th></th>
    </tr>

    @foreach (var item in Model)
    {
        <tr>

            <td>
                @Html.DisplayFor(modelItem => item.Name)
            </td>
            <td>
                @Html.DisplayFor(modelItem => item.Dob)
            </td>
            <td>
                @Html.DisplayFor(modelItem => item.EmailID)
            </td>
            @*<td>
                @Html.DisplayFor(modelItem => item.Password)
                </td>*@
            <td>
                @Html.DisplayFor(modelItem => item.PhoneNO)
            </td>
            <td>
                <img src="@Url.Content($"~/S_Images/{item.Image}")" alt="Image" width="100px" height="100px" />
            </td>
            <td>
                @Html.DisplayFor(modelItem => item.Gender)
            </td>
            <td>
                @Html.DisplayFor(modelItem => item.Address)
            </td>
            <td>
                @Html.DisplayFor(modelItem => item.City.CityName)
            </td>
            <td>
                @Html.DisplayFor(modelItem => item.ZipCode)
            </td>
            <td>
                @Html.ActionLink("Edit", "Edit", new { id = item.ID }) |
                @Html.ActionLink("Details", "Details", new { id = item.ID }) |
                @Html.ActionLink("Delete", "Delete", new { id = item.ID })
            </td>
        </tr>
    }

</table>

details:

@model VCS_MVC_project.Models.Student

@{
    ViewBag.Title = "Details";
}

<h2>Details</h2>

<div>
    <h4>Student</h4>
    <hr />
    <dl class="dl-horizontal">


        <dt>
            @Html.DisplayNameFor(model => model.Name)
        </dt>

        <dd>
            @Html.DisplayFor(model => model.Name)
        </dd>

        <dt>
            @Html.DisplayNameFor(model => model.Dob)
        </dt>

        <dd>
            @Html.DisplayFor(model => model.Dob)
        </dd>

        <dt>
            @Html.DisplayNameFor(model => model.EmailID)
        </dt>

        <dd>
            @Html.DisplayFor(model => model.EmailID)
        </dd>

        <dt>
            @Html.DisplayNameFor(model => model.Password)
        </dt>

        <dd>
            @Html.DisplayFor(model => model.Password)
        </dd>

        <dt>
            @Html.DisplayNameFor(model => model.PhoneNO)
        </dt>

        <dd>
            @Html.DisplayFor(model => model.PhoneNO)
        </dd>

        <dt>
            @Html.DisplayNameFor(model => model.Image)
        </dt>

        <dd>
            <img src="@Url.Content($"~/S_Images/{Model.Image}")" alt="Image" width="100px" height="100px" />
        </dd>

        <dt>
            @Html.DisplayNameFor(model => model.Gender)
        </dt>

        <dd>
            @Html.DisplayFor(model => model.Gender)
        </dd>

        <dt>
            @Html.DisplayNameFor(model => model.Address)
        </dt>

        <dd>
            @Html.DisplayFor(model => model.Address)
        </dd>

        <dt>
            @Html.DisplayNameFor(model => model.City)
        </dt>

        <dd>
            @Html.DisplayFor(model => model.CityId)
        </dd>

        <dt>
            @Html.DisplayNameFor(model => model.ZipCode)
        </dt>

        <dd>
            @Html.DisplayFor(model => model.ZipCode)
        </dd>

    </dl>
</div>
<p>
    @Html.ActionLink("Edit", "Edit", new { id = Model.ID }) |
    @Html.ActionLink("Back to List", "Index")
</p>

and how to edit uploaded image in this program

I am checking your code.

It will take some time.

I will get back to you tomorrow.