LINQ to Entities error when trying to bind a dropdownlist

I am trying to create a viewmodel a开发者_如何学Gond add a SelectListItem to allow me to bind a dropdown list. I have a very basic viewmodel that looks like this

  public class CreatePurchaseViewModel
{
    public Product Product { get; set; }
    public IEnumerable<SelectListItem> Products { get; set; }
    public int SelectedProductId { get; set; }
    public DateTime OrderDate { get; set; }
    public bool OrderSent { get; set; }

}

My controller looks like this

 [HttpGet]
    public ActionResult Create()
    {
        var model = new CreatePurchaseViewModel
                        {
                            Products = context.Products.Select(x =>
                                                        new SelectListItem()
                                                            {
                                                                Text = x.ProductName,
                                                                Value = x.ProductID
                                                            })
                        };
       return View(model);
    }

However it complains that Value = x.Product cant convert type int to string. So if I add a .ToString it compiles ok but when I try load the view I get an error

LINQ to Entities does not recognize the method 'System.String ToString()' method, and this method cannot be translated into a store expression.

My View

@using (Html.BeginForm()) {
@Html.ValidationSummary(true)
<fieldset>
    <legend>CreatePurchaseViewModel</legend>

    <div class="editor-label">
        @Html.LabelFor(model => model.SelectedProductId)
    </div>
    <div class="editor-field">
        @Html.DropDownListFor(x => x.SelectedProductId,Model.Products)
        @Html.ValidationMessageFor(model => model.SelectedProductId)
    </div>
    <div class="editor-label">
        @Html.LabelFor(model => model.OrderDate)
    </div>
    <div class="editor-field">
        @Html.TextBoxFor(model=>model.OrderDate)
        @Html.ValidationMessageFor(model => model.OrderDate)
    </div>
    <div>
    Sent
    @Html.RadioButtonFor(model => model.OrderSent, "Sent", new { @checked = true })
    Not Sent
    @Html.RadioButtonFor(model=>model.OrderSent,"Not Sent")

Im pretty new to both entity framework and mvc so any help would be great.

Thank you

---

You haven't specified how does your Product model look like but we can assume that the ProductID property is integer so you might need to convert it to a string:

[HttpGet]
public ActionResult Create()
{
    var model = new CreatePurchaseViewModel
    {
        Products = context.Products.Select(x =>
            new SelectListItem
            {
                Text = x.ProductName,
                Value = x.ProductID.ToString()
            }
        )
   };
   return View(model);
}