ASP.NET Core中具有Entity Framework Core的Razor页面-选择列表

如何解决ASP.NET Core中具有Entity Framework Core的Razor页面-选择列表

我正在学习如何在ASP.NET Core中使用Razor Pages，但是我真的对如何将其解析为Models感到困惑。（尝试过Item.ItemId无效）。所有属于“模型”的标签。即使我在模型中也是一个错误。从Microsoft文档〜国家示例输入代码。

在View .cshtml中：

<div class="form-group">
    @Html.LabelFor(x => **Model.SelectedRegionCode**,htmlAttributes: new { @class = "control-label col-md-2" })
    <div class="col-md-5">
        @Html.DropDownListFor(x => **Model.SelectedRegionCode**,new SelectList(Model.Regions,"Value","Text"),htmlAttributes: new { @class = "form-control",@id = "Region" })
        @Html.ValidationMessageFor(x => **x.SelectedRegionCode**,"",new { @class = "text-danger" })
    </div>
</div>

模型类：

public class Item
{
    public int ItemId { get; set; }
    public string ItemName { get; set; }
    public string ItemDescription { get; set; }
    public int DepotId { get; set; }

    public string Depots { get; set; }
    public string Tracking { get; set; }

    [display(Name = "Customer Number")]
    public string CustomerID { get; set; }

    [required]
    [display(Name = "Customer Name")]
    [StringLength(75)]
    public string CustomerName { get; set; }

    [required]
    [display(Name = "Country")]
    public string SelectedCountryIso3 { get; set; }
    public IEnumerable<SelectListItem> Countries { get; set; }

    [required]
    [display(Name = "State / Region")]
    public string SelectedRegionCode { get; set; }
    public IEnumerable<SelectListItem> Regions { get; set; }
}