Null Reference Exception When adding object to list [closed]

Answer 1

OrderiTems is null.

public virtual List<OrderItemInfo> OrderiTems { get; set; }

Try implementing set/get or storing an empty list into OrderiTems in the constructor.

Answer 2

Is DbNull is not the same as Is NULL!

You need to check for 'IS NULL', instead. That is why you are getting Null Reference Exceptions.

EDIT: as ebyrob got it right, the following line throws the exception:

this.OrderiTems.Add(oi); // NULL Reference HERE

Answer 3

It seems you never SET your property... You have it defined as a List<OrderItemInfo> type but you never initialize it to an instance of that type. Try initializing it in a constructor:

public class OrderInfo
{
    public OrderInfo
    {
        OrderiTems = new List<OrderItemInfo>();
    }
}

Answer 4

You need to instanciate the list before starting using it. A good place to do that is in the class constructor. Assuming you use the default constructor :

public OrderInfo()
{
    this.OrderiTems = new List<OrderItemInfo>();
}