public AppShell()
{
this.Loaded += (sender,args) => {
Current = this;
};
this.InitializeComponent();
DataContext = new MainPageViewModel();
this.RootSplitView.RegisterPropertyChangedCallback(
SplitView.DisplayModeProperty,
(s, a) =>
{
// Ensure that we update the reported size of the TogglePaneButton when the SplitView's
// DisplayMode changes.
this.CheckTogglePaneButtonSizeChanged();
});
SystemNavigationManager.GetForCurrentView().BackRequested += SystemNavigationManager_BackRequested;
}