在post action方法中获取Null模型

Question

我正在使用.NET Core MVC。我的问题是，在我的创建页面成功插入数据后，我一直在获取空模型。

1. NullReferenceException：对象引用未设置为Index.cshtml中的object.MoveNext实例
2. @foreach（模型中的酒厂酿酒厂）
3. ThrowForNonSuccess
4. HandleNonSuccessAndDebuggerNotification MoveNext

请告知。

这是我的显示页面：

@model IEnumerable<Winery>

@{ 
    ViewData["Title"] = "Wineries";
}

<h2>Wineries overview</h2>

<p>
    <a asp-action="Create">Create new</a>
</p>

<table class="table">
    <tr>
        <th>@Html.DisplayNameFor(Model => Model.Name)</th>
        <th>@Html.DisplayNameFor(Model => Model.Country)</th>
    </tr>

    @foreach (Winery winery in Model)
    {
        <tr>
            <td>
                @Html.DisplayFor(Model => winery.Name)
            </td>
        </tr>
        <tr>
            <td>
                @Html.DisplayFor(Model => winery.Country)
            </td>
        </tr>
    }
   
</table>

这是我的模特：

public class Winery
{
    [Key]
    public int Id { get; set; }
    [Required]
    [StringLength(30)]
    public string Name { get; set; }
    public Country Country { get; set; }
    public virtual ICollection<Wine> Wines { get; set; }
}

public enum Country
{
    France, Germany, Italy, India, Other
}

这是控制器：

public class WineriesController : Controller
{
    private ApplicationDbContext _context;

    public WineriesController(ApplicationDbContext context)
    {
        _context = context;
    }

    public IActionResult Index()
    {
        List<Winery> wineries = _context.Winery.ToList();
        return View();
    }

    [HttpGet]
    public IActionResult Create()
    {
        return View();
    }

    [HttpPost]
    [ValidateAntiForgeryToken]
    public IActionResult Create(Winery viewModel)
    {
        if(ModelState.IsValid)
        {
            _context.Winery.Add(viewModel);
            _context.SaveChanges();

            return RedirectToAction("Index");
        }

        return View(viewModel);
    }
}