Androide:

Puede usar CreateBottomNavViewAppearanceTracker para cambiar algo para la vista inferior.

 [assembly: ExportRenderer(typeof(AppShell), typeof(ShellCustomRenderer))] namespace ShellDemo.Droid { class ShellCustomRenderer : ShellRenderer { public ShellCustomRenderer(Context context) : base(context) { } protected override IShellBottomNavViewAppearanceTracker CreateBottomNavViewAppearanceTracker(ShellItem shellItem) { return new CustomBottomNavAppearance(); } } public class CustomBottomNavAppearance : IShellBottomNavViewAppearanceTracker { public void Dispose() { } public void ResetAppearance(BottomNavigationView bottomView) { } public void SetAppearance(BottomNavigationView bottomView, IShellAppearanceElement appearance) { //put your code here } } }

• Shadow: Crea un Shadow.xml en Drawable de Android.

   <shape xmlns:android="http://schemas.android.com/apk/res/android"> <gradient android:startColor="@android:color/holo_orange_light" android:endColor="@android:color/transparent" android:angle="90" /> </shape>

  Y luego configure la sombra como fondo de la vista inferior en SetAppearance.

   bottomView.SetBackgroundResource(Resource.Drawable.shadow);

• Línea de borde de la vista inferior. Cree un Border_top.xml en Drawable de Android.

   <layer-list xmlns:android="http://schemas.android.com/apk/res/android"> <item android:top="5dip"> <shape> <solid android:color="@android:color/holo_green_light"> </solid> </shape> </item> </layer-list>

  Y luego configúralo como fondo.

   bottomView.SetBackgroundResource(Resource.Drawable.border_top);

iOS:

Puede usar CreateTabBarAppearanceTracker para cambiar la barra de pestañas.

 [assembly: ExportRenderer(typeof(AppShell), typeof(ShellCustomRenderer))] namespace ShellDemo.iOS { public class ShellCustomRenderer : ShellRenderer { protected override IShellTabBarAppearanceTracker CreateTabBarAppearanceTracker() { return new TabBarAppearance(); } } public class TabBarAppearance : IShellTabBarAppearanceTracker { public void Dispose() { } public void ResetAppearance(UITabBarController controller) { } public void SetAppearance(UITabBarController controller, ShellAppearance appearance) { } public void UpdateLayout(UITabBarController controller) { } } }

Sombra: el iOS tiene una sombra predeterminada allí.