EF4 - Add object to objectcontext without savechanges

I have a page like Order - Order lines. Order represents by some textboxes and ddl开发者_C百科s, Order lines represents by GridView.

I want to let users add order lines without save changes to database. For example: he adds 4 order lines, fill order info and then hits Save button. Only an that moment all information should be saved to DB.

When I use code like

using (Entities ctx = new Entities())
{
 //create new OrderLine
 OrderLine ol = OrderLine.CreateOrderLine(1, 1, "", 1);
 //add OrderLine to OrderLines collection
 ctx.CreateOrderLines.AddObject(ol);
}

newly created OrderLine does not appears in my object context, so I can't access it and bind GridView to new OrderList collection.

How can I solve this problem? Or maybe there are another ways to perform this task?

Thanks.

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You could try to detach the Order object and work with it until you are ready to save it back to the database.