System.Web.Mvc.WebViewPage .Model.get返回null

Home Controller

public ActionResult Index()
{
    using (MvcDB dataBase = new MvcDB())
    {

    }
    return View();
}

public void DataDoldur()
{
    using (MvcDB dataBase = new MvcDB())
    {
        Kategori ktgr1 = new Kategori();
        ktgr1.KategoriAdi = "Spor";
        dataBase.Kategori.Add(ktgr1);

        dataBase.SaveChanges();
    }

}
public ActionResult Index()
{