ASP.NET MVC5 Entity Framework Group Kentät (maa, osavaltio) tilille

Minulla on yritys-, maa- ja osavaltioluokat. Osavaltio liittyy maahan Osavaltio ja maa ovat yrityksen ulkoavain

Ongelma Yritysnäkymä näyttää sekä osavaltion että maan erillisinä pudotusvalikoina. Mutta odotan, että kun valitsen Osavaltion, vastaavan maan pitäisi muuttua tai päinvastoin. Onko tämä mahdollista MVC5 EF -mallissa.

Yritysluokka

public class Company
{
    public int CompanyID { get; set; }
    [Required]
    [StringLength(100,MinimumLength=3)]
    public string Name { get; set; }
    [StringLength(200)]
    public string Address { get; set; }
    public int? StateID { get; set; }
    public virtual State State { get; set; }
    public int? CountryID { get; set;}
    public virtual Country Country { get; set; }
    public int CompanyTypeID { get; set; }
    public virtual CompanyType CompanyType { get; set; }

}

Maaluokka

public class Country
{
    public int CountryID { get; set; }
    [Required]
    [StringLength(100)]
    public string Name { get; set; }
    public virtual ICollection<State> States { get; set; }
    public virtual ICollection<Company> Companies { get; set; }
}

Valtion luokka

public class State
{
    public int StateID { get; set; }
    [Required]
    [StringLength(100)]
    public string Name { get; set; }
    public int CountryID { get; set; }
    public virtual Country Country { get; set; }

    public virtual ICollection<Company> Companies { get; set; }

}

Olen rakentanut ja luonut näkymän ja yritysnäkymän viitteeksi

@using (Html.BeginForm()) {
@Html.AntiForgeryToken()

<div class="form-horizontal">
    <h4>Company</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.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.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.StateID, "StateID", htmlAttributes: new { @class = "control-label col-md-2" })
        <div class="col-md-10">
            @Html.DropDownList("StateID", null, htmlAttributes: new { @class = "form-control" })
            @Html.ValidationMessageFor(model => model.StateID, "", new { @class = "text-danger" })
        </div>
    </div>

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

    <div class="form-group">
        @Html.LabelFor(model => model.CompanyTypeID, "CompanyTypeID", htmlAttributes: new { @class = "control-label col-md-2" })
        <div class="col-md-10">
            @Html.DropDownList("CompanyTypeID", null, htmlAttributes: new { @class = "form-control" })
            @Html.ValidationMessageFor(model => model.CompanyTypeID, "", 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> } <div> @Html.ActionLink("Back to List", "Index")

@section Skriptit { @Scripts.Render("~/bundles/jqueryval") }

Kaikki apu olisi tervetullutta