private void RaiseForwardRequested()
{
DebugWrite();
var args = new HandledRoutedEventArgs();
ForwardRequested?.Invoke(null, args);
if (args.Handled)
{
return;
}
foreach (var frame in WindowContext.GetForCurrentView().NavigationServices.Select(x => x.FrameFacade))
{
frame.RaiseForwardRequested(args);
if (args.Handled)
{
return;
}
}
NavigationService?.GoForward();
}
/// <summary>
/// Default Hardware/Shell Back handler overrides standard Back behavior
/// that navigates to previous app in the app stack to instead cause a backward page navigation.
/// Views or Viewodels can override this behavior by handling the BackRequested
/// event and setting the Handled property of the BackRequestedEventArgs to true.
/// </summary>
private void RaiseBackRequested(Windows.System.VirtualKey key, ref bool handled)
{
DebugWrite();
var args = new HandledRoutedEventArgs();
BackRequested?.Invoke(null, args);
if (handled = args.Handled)
{
return;
}
var popups = VisualTreeHelper.GetOpenPopups(Window.Current);
foreach (var popup in popups)
{
if (popup.Child is INavigablePage page)
{
if (key == Windows.System.VirtualKey.Escape)
{
if (popup.Child is INavigatingPage navigating)
{
navigating.OnBackRequesting(args);
}
args.Handled = true;
}
else
{
page.OnBackRequested(args);
}
if (handled = args.Handled)
{
return;
}
}
else if (popup.Child is ContentDialog dialog)
{
dialog.Hide();
return;
}
else if (key == Windows.System.VirtualKey.Escape)
{
handled = args.Handled = true;
return;
}
}
foreach (var frame in WindowContext.GetForCurrentView().NavigationServices.Select(x => x.FrameFacade).Reverse())
{
frame.RaiseBackRequested(args);
if (handled = args.Handled)
{
return;
}
}
if (NavigationService?.CanGoBack ?? false)
{
NavigationService?.GoBack();
}
}