Xamarin.Forms 实现页面全屏显示
NavigationPage.SetHasNavigationBar(this, false)或者<ContentPage ... NavigationPage.HasNavigationBar="{Binding IsFullScreen}"></ContentPage>
NavigationPage.SetHasNavigationBar(this, false)或者<ContentPage ... NavigationPage.HasNavigationBar="{Binding IsFullScreen}"></ContentPage>