This method will be called when the DockWindow gains focus following the user clicking on the associated Button in the Ribbon, or clicking anywhere within the DockWindow itself; if the DockWindow already has focus, this method is not called again. This method is also called after the window is shown, after the OnShow method. The corresponding OnDeactivate()()() method is called when the DockWindow loses focus.

A common use of this method is to update the DockWindow user interface when changes are required in response changes to state of the application, if those changes cannot be made in response to events.