How to keep fieldManager in Stack

When i put a VerticalFieldManager to a Stack and delete all items in VerticalFieldManager, the VerticalFieldManager in Stack is also changing.

Does Stack keep refe开发者_StackOverflow中文版rence of object? If so, how can I keep managers in a Stack?

Does Stack keep reference of object?

Yes, it works as any other Java container, such as a Vector for example.

If so, how can I keep managers in a Stack?

Not sure what are you talking about. Once you have put an Object into container the Object is already kept by the container.

Probably say what are you trying to achieve with putting managers in a Stack.