You handle Navigated if you need to discover pertinent information regarding the navigation request when downloading commences. This information is available from the NavigationEventArgs object that is passed to the Navigated event handler, and includes:
The source page. When Navigated is raised, at least part of the source page's user interface (UI) tree has been parsed, and attached to target content control.
Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)