PortablePrism.Portable by Andrii Chebukin

<PackageReference Include="PortablePrism.Portable" Version="1.0.1" />

 INavigationAware

public interface INavigationAware
Implementing this interface allows viewmodel be notified about navigation by ViewModelAwarePage.

Invoked immediately after the Page is unloaded and is no longer the current source of a parent Frame.

Invoked when the Page is loaded and becomes the current source of a parent Frame.

Invoked immediately before the Page is unloaded and is no longer the current source of a parent Frame.