c#如何为集合的集合编码支持共享同步

I have searched the whole internet looking for solution w/o result. In my program, I have UI thread where I display in two datagrids Customers and Orders. Orders are displayed for selected customer. Definition of collections and their update happens in the background. UI purpose is only to display up to date information. I take advantage of the latest functionality introduced in C# 4.5 that is: BindingOperations.EnableCollectionSynchronization method. In my program I have class Customers that defines a collection of Customer class. In turn Customer class defines a collection of Order class. My problem is that I do not know I have searched the whole internet looking for