PHP自己不工作

Question

表单提交时我没有收到输出。这是我目前的努力。我是php的新手，尝试了各种技术，但似乎没有任何工作。该文件只刷新一个空页。

public ActionResult Create()
    {
        var catlist = db.Categories.Select(x => new { id = x.id, name = x.name }).ToList();
        SelectList sl = new SelectList(catlist.AsEnumerable(), "id", "name");
        ViewBag.SelectCategories = sl;

        var countrylist = db.CountryTb.Select(x => new { id = x.id, name = x.name }).ToList();
        SelectList s2 = new SelectList(countrylist.AsEnumerable(), "id", "name");
        ViewBag.SelectCountry = s2;

        return View();

    }

    [HttpPost]
    public ActionResult Create(Item i)
    {
        db.Items.Add(i);
        db.SaveChanges();
        return RedirectToAction("Index");

    }