无法将“ WareHouse”上的“ ModifiedOn”属性设置为“ DateTime”值您必须将此属性设置为\'String\'类型的非空值

如何解决无法将“ WareHouse”上的“ ModifiedOn”属性设置为“ DateTime”值您必须将此属性设置为\'String\'类型的非空值

|| 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 \”操作时，就会发生问题 \“无法将\'WareHouse \'的\'ModifiedOn \'属性设置为\'DateTime \'值。您必须将此属性设置为类型为''String \'的非空值。\” 即使我在ModifyOn字段中也没有空条目。请检查并建议我犯了什么错误。     

解决方法

        该物业的

Database Type

和

POCO Type

之间可能存在类型不匹配的情况。如果我不得不猜测您的媒体资源类型是

String

或不可为null的DateTime，并且它应该为可为null的

DateTime

，即：

public DateTime? ModifiedOn { get; set; }