private void RefreshAppViewBackButtonVisibility(NavigationServiceBase sender)
{
if (sender == null)
{
throw new ArgumentNullException("sender");
}
if (((CrystalApplication)CrystalApplication.Current).Options.HandleBackButtonForTopLevelNavigation)
{
SystemNavigationManager.GetForCurrentView().AppViewBackButtonVisibility =
sender.CanGoBackward ? AppViewBackButtonVisibility.Visible : AppViewBackButtonVisibility.Collapsed;
}
}
/// <summary>
/// Registers the NavigationService with the NavigationManager.
/// </summary>
/// <param name="service">The NavigationService to be registered.</param>
internal void RegisterNavigationService(NavigationServiceBase service)
{
//Null check.
if (service == null)
{
throw new ArgumentNullException("service");
}
//Check if the user is trying to register a top-level Navigation Service.
if (RootNavigationService != null && service.NavigationLevel == FrameLevel.One)
{
throw new Exception("There can only be one level-one navigation service.");
}
//If it isn't already in the list, add it.
if (!navigationServices.Contains(service))
{
navigationServices.Add(service);
}
}
public void RegisterCustomNavigationService(NavigationServiceBase service, FrameLevel frameLevel = FrameLevel.Two)
{
//Check if the user is trying to register a top-level Navigation Service.
if (RootNavigationService != null && frameLevel == FrameLevel.One)
{
throw new Exception("There can only be one level-one navigation service.");
}
//If it isn't already in the list, add it.
if (navigationServices.Any(x => x.NavigationLevel == frameLevel))
{
throw new Exception();
}
if (service == null)
{
throw new ArgumentNullException(nameof(service));
}
service.NavigationLevel = frameLevel;
service.NavigationManager = this;
navigationServices.Add(service);
}