Unable to Delete record from database using MVC 4

Question

I am trying to delete data using MVC in my application. For this first I am fetching the records from the database into the labels. Then I am trying to delete this. The code which I am writing is below

This is the code of my Controller

public ActionResult Delete(string id)
        {
            DBData dbData = new DBData();
            StudentData sd = new StudentData();
            DataSet ds;
            ds = dbData.SelectUserById(id);
            sd.SID = Convert.ToInt32(ds.Tables[0].Rows[0]["sid"].ToString());

            sd.StudentName = ds.Tables[0].Rows[0]["studentname"].ToString();
            sd.ContactNo = ds.Tables[0].Rows[0]["contactno"].ToString();
            sd.EmailId = ds.Tables[0].Rows[0]["emailid"].ToString();

            return View(sd);
        }
        [HttpPost]
        public ActionResult Delete(StudentData sd)
        {
            if (ModelState.IsValid)
            {
                DBData db = new DBData();
                db.DeleteRecord(sd);
                return RedirectToAction("SelectAllStudent", "Student");
            }
            else
            {
                ModelState.AddModelError("", "Error while Deleting data");
                return View();
            }
        }

Here is my model

 public void DeleteRecord(StudentData sd)
        {
            SqlConnection con = new SqlConnection();
            try
            {
                con.ConnectionString = ConfigurationManager.ConnectionStrings["con"].ConnectionString;
                if (con.State == ConnectionState.Closed)
                {
                    con.Open();
                }
                SqlCommand cmd = new SqlCommand("delete from studentinfo where sid=@sid", con);
                cmd.CommandType = CommandType.Text;
                cmd.Parameters.AddWithValue("@sid", sd.SID);
                cmd.ExecuteNonQuery();
                cmd.Dispose();
            }
            catch
            {
            }
            finally
            {
                con.Close();
            }
        }

as you see StudentData is a class in which I define properties.

Now here is my View

@model CrudMVC.Models.StudentData

@{
    ViewBag.Title = "Delete";
}

<h2>Delete</h2>

<h3>Are you sure you want to delete this?</h3>
<fieldset>
    <legend>StudentData</legend>

    <div class="display-label">
         @Html.DisplayNameFor(model => model.SID)
    </div>
    <div class="display-field">
        @Html.DisplayFor(model => model.SID)
    </div>

    <div class="display-label">
         @Html.DisplayNameFor(model => model.StudentName)
    </div>
    <div class="display-field">
        @Html.DisplayFor(model => model.StudentName)
    </div>

    <div class="display-label">
         @Html.DisplayNameFor(model => model.EmailId)
    </div>
    <div class="display-field">
        @Html.DisplayFor(model => model.EmailId)
    </div>

    <div class="display-label">
         @Html.DisplayNameFor(model => model.ContactNo)
    </div>
    <div class="display-field">
        @Html.DisplayFor(model => model.ContactNo)
    </div>
</fieldset>
@using (Html.BeginForm()) {
    <p>
        <input type="submit" value="Delete" /> |
        @Html.ActionLink("Back to List", "SelectAllStudent")
    </p>
}

Now when I am trying to delete my record everytime,not a single record was deleted .I add breakpoint and check the values. But In HttpPost function StudentData sd had not any single value. Its show me null.Why these properties are empty I dnt know. Please experts Help me to get out of this error

Answer 1

You do not have any inputs within you form element to post back (note Html.DisplayFor() methods do not render html inputs)

@using (Html.BeginForm()) {
  @Html.EditorFor(model => model.SID)
  @Html.EditorFor(model => model.StudentName)
  // Other properties here
  <input type="submit" value="Delete" />
}

If you don't want editable fields you can create hidden inputs for all properties or consider just posting back the ID and modifying you controller action