private void Nav_BackRequested(object sender, BackRequestedEventArgs e)
{
if (SubstitutionBackNavigation.Count > 0)
{
var substitutionBackNavPair = SubstitutionBackNavigation.Last();
var action = substitutionBackNavPair.Value;
if (SubstitutionBackNavigation.Count == 0)
{
var nav = Windows.UI.Core.SystemNavigationManager.GetForCurrentView();
nav.BackRequested -= Nav_BackRequested;
// バックナビゲーションが出来ない場合にBackButtonを非表示に
var pageManager = App.Current.Container.Resolve <PageManager>();
if (!pageManager.NavigationService.CanGoBack())
{
nav.AppViewBackButtonVisibility = Windows.UI.Core.AppViewBackButtonVisibility.Collapsed;
}
}
if (action?.Invoke() ?? false)
{
SubstitutionBackNavigation.Remove(substitutionBackNavPair.Key);
}
e.Handled = true;
}
}
protected void AddSubsitutionBackNavigateAction(string id, Func <bool> action)
{
if (!SubstitutionBackNavigation.ContainsKey(id))
{
SubstitutionBackNavigation.Add(id, action);
var nav = Windows.UI.Core.SystemNavigationManager.GetForCurrentView();
nav.AppViewBackButtonVisibility = Windows.UI.Core.AppViewBackButtonVisibility.Visible;
nav.BackRequested += Nav_BackRequested;
}
}
protected bool RemoveSubsitutionBackNavigateAction(string id)
{
if (SubstitutionBackNavigation.ContainsKey(id))
{
if (SubstitutionBackNavigation.Count == 1)
{
var nav = Windows.UI.Core.SystemNavigationManager.GetForCurrentView();
nav.BackRequested -= Nav_BackRequested;
// バックナビゲーションが出来ない場合にBackButtonを非表示に
var pageManager = App.Current.Container.Resolve <PageManager>();
if (!pageManager.NavigationService.CanGoBack())
{
nav.AppViewBackButtonVisibility = Windows.UI.Core.AppViewBackButtonVisibility.Collapsed;
}
}
return(SubstitutionBackNavigation.Remove(id));
}
else
{
return(false);
}
}
