AddToCart return Redirect(TempData["returnURL"].ToString());

[SiMonChit]

In Product1Controller
I get the error so How to fixed and why this error
Can you explain me sir.

public ActionResult AddToCart(int id)
{
OrderDetail OD = new OrderDetail();
OD.ProductID = id;
int Qty = 1;
decimal price = db.Products.Find(id).UnitPrice;
OD.Quantity = Qty;
OD.UnitPrice = price;
OD.TotalAmount = Qty * price;
OD.Product = db.Products.Find(id);

        if (TempShpData.items == null)
        {
            TempShpData.items = new List<OrderDetail>();
        }
        TempShpData.items.Add(OD);
        AddRecentViewProduct(id);
        return Redirect(TempData["returnURL"].ToString());

    }

System.NullReferenceException: 'Object reference not set to an instance of an object.'

System.Web.Mvc.TempDataDictionary.this[string].get returned null.

[KavinTony01]

Since you are not pushing any values to the TempData["returnURL"], you are getting null reference exception.

You can use
return RedirectToAction("Index", "MyCart");

[alienware-net]

Can you help me how to connect the db with the project or how to get started with the project. I didn't know R49_MyEcommerceDB file and MyEcommerceDbContext is the same? I have restored R49_MyEcommerceDB in sql server; add new model of data with R49_MyEcommerceDB in visual studio but can't not run. It has the error like this

System.Data.Entity.ModelConfiguration.ModelValidationException: 'One or more validation errors were detected during model generation:

MyEcommerceAdmin.Models.admin_Employee: : EntityType 'admin_Employee' has no key defined. Define the key for this EntityType.
MyEcommerceAdmin.Models.admin_Login: : EntityType 'admin_Login' has no key defined. Define the key for this EntityType.
MyEcommerceAdmin.Models.genPromoRight: : EntityType 'genPromoRight' has no key defined. Define the key for this EntityType.
MyEcommerceAdmin.Models.OrderDetail: : EntityType 'OrderDetail' has no key defined. Define the key for this EntityType.
MyEcommerceAdmin.Models.RecentlyView: : EntityType 'RecentlyView' has no key defined. Define the key for this EntityType.
MyEcommerceAdmin.Models.PaymentType: : EntityType 'PaymentType' has no key defined. Define the key for this EntityType.
MyEcommerceAdmin.Models.ShippingDetail: : EntityType 'ShippingDetail' has no key defined. Define the key for this EntityType.
MyEcommerceAdmin.Models.genMainSlider: : EntityType 'genMainSlider' has no key defined. Define the key for this EntityType.
admin_Employee: EntityType: EntitySet 'admin_Employee' is based on type 'admin_Employee' that has no keys defined.
admin_Login: EntityType: EntitySet 'admin_Login' is based on type 'admin_Login' that has no keys defined.
genPromoRights: EntityType: EntitySet 'genPromoRights' is based on type 'genPromoRight' that has no keys defined.
OrderDetails: EntityType: EntitySet 'OrderDetails' is based on type 'OrderDetail' that has no keys defined.
RecentlyViews: EntityType: EntitySet 'RecentlyViews' is based on type 'RecentlyView' that has no keys defined.
PaymentTypes: EntityType: EntitySet 'PaymentTypes' is based on type 'PaymentType' that has no keys defined.
ShippingDetails: EntityType: EntitySet 'ShippingDetails' is based on type 'ShippingDetail' that has no keys defined.
genMainSliders: EntityType: EntitySet 'genMainSliders' is based on type 'genMainSlider' that has no keys defined.
'