void navigation_BeginTransition(object sender, ChangedEventArgs<int> e) { inTransition = true; int index = e.NewValue; transitionTabItem = pages[e.NewValue]; string title = Title; header.AnimLabel.Text = back ? title : transitionTabItem.Title; Title = back ? transitionTabItem.Title : title; #if SUPPORT_ALPHA ButtonGroup bg = EnsureAnimButtons(); bg.BeginInit(); bg.Buttons.Clear(); foreach (FluidButton b in tabs[index].Buttons) bg.Buttons.Add(b); bg.EndInit(); FluidButton back = EnsureAnimBackButton(); back.Alpha = 0; back.Visible = index > 0; back.Text = index > 0 ? tabs[index - 1].Title : ""; bg.Visible = bg.Buttons.Count > 0; bg.Alpha = 0; #endif }