When is NavigationService initialized?

Question

I want to catch the NavigationService.Navigating event from my Page, to prevent the user from navigating forward. I have an event handler defined thusly:

void Pr         


        

Answer 1

NavigationService.Navigate triggers both a NavigationService.Navigating event AND an Application.Navigating event. I solved this problem with the following:

public class PageBase : Page
{
    static PageBase()
    {
        Application.Current.Navigating += NavigationService_Navigating;
    }

    protected static void NavigationService_Navigating(object sender, NavigatingCancelEventArgs e)
    {
        // put your event handler code here...
    }
}