Somewhere, I have
Order o = db.Orders.First(o => o.ID == 6);
...
o.Details.Add(new OrderDetail(1,2));
and in button click event
...
Order o1 = db.Orders.FirstOrDefault(o2=>o2.ID == o.ID);
o1.Details.Clear();
foreach(OrderDetail od in o.Details){
o.Details.Add(od);
}
db.SaveChange();
...
I meet this error:
An unhandled exception of type 'System.InvalidOperationException' occurred in System.Data.Entity.dll
Additional information: The relationship between the two objects cannot be defined because they are attached to different ObjectContext objects
It's seem like I cannot modify the object which created by another DbContext or by hand, is there a workround way?