Returns the panel that resizes together with the panel dragged by an end-user.
A DockPanel object that is the panel that resizes together with the panel dragged by an end-user.
When end-users resize a panel, the DockManager.Sizing event raises. In this event, you can read the DockPanelEventArgs.Panel property to identify what panel a user resizes. To retrieve a neighboring panel that has to change its size in accordance with the primary panel, use the SidePanel property.