Automatic Lazyloading on Entity Framework 4.0

Question

Suppose I have an Entity Order with OrderDetails as child preperty.

I enable lazyloading like this:

  _context.ContextOptions.LazyLoadingEnabled = true;

I Can feed a view with a method like this:

Order.GetAll()

And navigate by the order details automatically without getting the wirerd "Object reference not set to an instance of an object" error??

Answer 1

If you have lazy loading, when you load up the objects you need to explicitly include the sub objects.

So Order.GetAll() will include

return context.Orders.Include("OrderDetails");

Another alternative is to load up the order details later, like so:

if (!order.OrderDetailsHeaders.IsLoaded)
{
    order.OrderDetailsHeaders.Load();
}