绑定文本框以在MVC4中建模

Question

In my MVC application, I have specified two conditions based on the Model.Count to display the values in View.
View

  @model IEnumerable<SampleECommerce.Models.DetailsModel>
  @using (Html.BeginForm("Details", "Grid", new { UserID = Request.QueryString["UserID"], partnerid = Request.QueryString["Partnerid"] }, FormMethod.Post))
    {
    if (Model.Count() == 0)
    {
    @foreach (var item in Model)
    {
        <table>
            <tr>
                <td>
                    @Html.DisplayNameFor(model => model.FirstName)
                    <input id="FirstName" type="text" class="TextBoxBorder" name="FirstName" value="@item.FirstName" /> // When the Model count is zero, the label and textbox is not displayed.
                </td>
            </tr>
        </table>
    }
    else
    {
    @foreach (var item in Model)
    {
        <table>
            <tr>
                <td>
                    @Html.DisplayNameFor(model => model.FirstName)
                    <input id="MFirstName" type="text" class="TextBoxBorder" name="FirstName" value="@item.FirstName" />
                </td>
            </tr>
        </table>
    }

Controller

    public ActionResult Details()
       {
           string userid = Request.QueryString["UserID"];
           string partnerid = Request.QueryString["Partnerid"];

           con.Open();
           SqlCommand cmd = new SqlCommand("select FirstName from Details where UserID = +userid+", con);

       SqlDataReader dr = cmd.ExecuteReader();
       List<DetailsModel> objmodel = new List<DetailsModel>();
       while (dr.Read())
       {
           objmodel.Add(new DetailsModel()
           {
               FirstName = dr["First Name"].ToString(),


           });
       }
       dr.Close();

       return View(objmodel);
   }

When the Model.Count is zero, the label and textbox are not displayed.
I am trying to insert new value to textbox when the model.count is zero based on the userid
I tried to bind the textbox to model all the ways specified in the Link .
1. @Html.TextBoxFor(model => model.FirstName) Error in FirstName stating "System.Collections.Generic.IEnumerable doesnot find definition for FirstName or no extension method "
2. @Html.TextBox(model=>model.FirstName) "Error stating Cannot convert Lamba expression to string type"
How to bind and display the textbox value to the model when the model.count is zero. Any suggestions ??

Answer 1

when the Model.Count is 0, foreach does nothing .

  @model IEnumerable<SampleECommerce.Models.DetailsModel>
  @using (Html.BeginForm("Details", "Grid", new { UserID = Request.QueryString["UserID"], partnerid = Request.QueryString["Partnerid"] }, FormMethod.Post))
    {
        <table>
        if (Model.Count() == 0)
        {

                <tr>
                    <td>
                        @Html.DisplayNameFor(model => model.FirstName)
                        <input id="FirstName" type="text" class="TextBoxBorder" name="FirstName" /> // When the Model count is zero, the label and textbox is not displayed.
                    </td>
                </tr>
        }
        else
        {
                @foreach (var item in Model)
                {

                        <tr>
                            <td>
                                @Html.DisplayNameFor(model => model.FirstName)
                                <input id="MFirstName" type="text" class="TextBoxBorder" name="FirstName" value="@item.FirstName" />
                            </td>
                        </tr>

                }
        }
        <tr>
            <td>
                <input type="submit" value="submit" />
            </td>
        </tr>
        </table>
    }