public NavigationService(Frame frame)
{
FrameFacade = new FrameFacade(frame);
FrameFacade.Navigating += async (s, e) =>
{
if (e.Suspending)
return;
// allow the viewmodel to cancel navigation
e.Cancel = !NavigatingFrom(false);
if (!e.Cancel)
{
await NavigateFromAsync(false);
}
};
FrameFacade.Navigated += (s, e) =>
{
NavigateTo(e.NavigationMode, e.Parameter);
};
}
public NavigationService(Frame frame)
{
FrameFacade = new FrameFacade(frame);
FrameFacade.Navigating += async(s, e) =>
{
if (e.Suspending)
{
return;
}
// allow the viewmodel to cancel navigation
e.Cancel = !NavigatingFrom(false);
if (!e.Cancel)
{
await NavigateFromAsync(false);
}
};
FrameFacade.Navigated += (s, e) =>
{
NavigateTo(e.NavigationMode, e.Parameter);
};
}
public void SaveNavigation()
{
if (CurrentPageType == null)
{
return;
}
var state = FrameFacade.PageStateContainer(GetType());
if (state == null)
{
throw new InvalidOperationException("State container is unexpectedly null");
}
state["CurrentPageType"] = CurrentPageType.ToString();
try { state["CurrentPageParam"] = CurrentPageParam; }
catch
{
throw new Exception("Failed to serialize page parameter, override/implement ToString()");
}
state["NavigateState"] = FrameFacade?.GetNavigationState();
}
void NavigateTo(NavigationMode mode, object parameter)
{
LastNavigationParameter = parameter;
LastNavigationType = FrameFacade.Content.GetType().FullName;
if (mode == NavigationMode.New)
{
// TODOAzureSample: clear existing state
}
var page = FrameFacade.Content as FrameworkElement;
if (page != null)
{
var dataContext = page.DataContext as INavigable;
if (dataContext != null)
{
// prepare for state load
dataContext.NavigationService = this;
var pageState = FrameFacade.PageStateContainer(page.GetType());
dataContext.OnNavigatedTo(parameter, mode, pageState);
}
}
}
