'WareHouse'上的'ModifiedOn'属性无法设置为'DateTime'值。您必须将此属性设置为“String”类型的非null值

Question

这是我的控制器类。

namespace CalcoWOMS.Controllers
{ 
    public class AdminController : Controller
    {
        private WOMSEntities db = new WOMSEntities();

        public ViewResult WareHouseIndex()
        {
            return View(db.WareHouse.ToList());
        }



        public ViewResult WareHouseDetails(int id)
        {
            WareHouse wareHouse = db.WareHouse.Single(m => m.ID == id);
            return View(wareHouse);
        }

        public ActionResult WareHouseCreate()
        {
            return View();
        }


        [HttpPost]
        public ActionResult Create(WareHouse wareHouse)
        {
            if (ModelState.IsValid)
            {
                db.WareHouse.AddObject(wareHouse);
                db.SaveChanges();
                return RedirectToAction("WareHouseIndex");
            }

            return View(wareHouse);
        }

        //
        // GET: /Admin/Edit/5

        public ActionResult WareHouseEdit(int id)
        {
            WareHouse wareHouse = db.WareHouse.Single(m => m.ID == id);
            return View(wareHouse);
        }



        [HttpPost]
        public ActionResult WareHouseEdit(WareHouse wareHouse)
        {
            if (ModelState.IsValid)
            {
                db.WareHouse.Attach(wareHouse);
                db.ObjectStateManager.ChangeObjectState(wareHouse, EntityState.Modified);
                db.SaveChanges();
                return RedirectToAction("WareHouseIndex");
            }
            return View(wareHouse);
        }

        //
        // GET: /Admin/Delete/5

        public ActionResult WareHouseDelete(int id)
        {
            WareHouse wareHouse = db.WareHouse.Single(m => m.ID == id);
            return View(wareHouse);
        }


        [HttpPost, ActionName("WareHouseDelete")]
        public ActionResult WareHouseDeleteConfirmed(int id)
        {
            WareHouse wareHouse = db.WareHouse.Single(m => m.ID == id);
            db.WareHouse.DeleteObject(wareHouse);
            db.SaveChanges();
            return RedirectToAction("WareHouseIndex");
        }
    }
}

这是我的桌子设计..

每当我想运行“Admin / WareHouseIndex”动作时，就会出现问题 “'WareHouse'上的'ModifiedOn'属性无法设置为'DateTime'值。您必须将此属性设置为'String'类型的非null值。”

即使我在modifiedOn字段中没有空条目。请检查一下，并告诉我我做了什么错误。

Answer 1

您的Database Type和POCO Type之间可能存在不匹配的类型。如果我不得不猜测我会说你的属性类型是String或不可为空的DateTime，它应该是可以为空的DateTime，即：

public DateTime? ModifiedOn { get; set; }