public MainPage() { this.InitializeComponent(); ShowStatusBar(); if (DeviceTypeHelper.GetDeviceFromFactorType() == DeviceFromFactorType.Phone) { Debug.WriteLine("current:" + _currentViewHeight + "; initial:" + InitialViewHeight + "; BarStatus:" + IsSystemVirtualButtonBarShow); ApplicationView.GetForCurrentView().VisibleBoundsChanged += (sender, e) => { _currentViewHeight = ApplicationView.GetForCurrentView().VisibleBounds.Height; Debug.WriteLine("current:" + _currentViewHeight + "; initial:" + InitialViewHeight + "; BarStatus:" + IsSystemVirtualButtonBarShow); MessagingCenter.Send <YahooTWBuy.Pages.MainPage, bool>((YahooTWBuy.Pages.MainPage)MainApp.MainPage, "UWP_SystemVirtualButtonBarStatus", IsSystemVirtualButtonBarShow); }; } LoadApplication(MainApp); }