Application Life Cycle
WHAT’S NEW IN WINDOWS 8.1
Windows 8.1 has removed the LayoutAwarePage from the templates. In Windows 8.0, the LayoutAwarePage was the base class for the BasicPage and exposed the events and methods necessary for saving and loading state. The BasicPage in Windows 8.1 declares a local instance of the NavigationHelper class and ties into the navigation events in the page constructor. A Windows 8.0 app retargeted for Windows 8.1 will have issues if it is using the LayoutAwarePage.
The Load and Save event handlers have been cleaned up significantly due to this change. Instead of including the PageState object directly ...