Xamarin Forms - iOS TabbedPage Tab Font Overrides

ExtendedTabbedPageRenderer.cs

using System;
using {AppName}.iOS.Renderers;
using UIKit;
using Xamarin.Forms;
using Xamarin.Forms.Platform.iOS;
using {AppName}.iOS.Views;

[assembly: ExportRenderer(typeof(TabbedPage), typeof(ExtendedTabbedPageRenderer))]
namespace {AppName}.iOS.Renderers
{
    /// <summary>
    /// This subclass of <see cref="TabbedRenderer"/> changes the appearance of the pages attached to a <see cref="TabbedPage"/> instance.
    /// </summary>
    public class ExtendedTabbedPageRenderer : TabbedRenderer
    {
        /// <summary>
        /// This method is overridden to allow the tab bar items to have their fonts updated appropriately.
        /// </summary>
        /// <param name="animated">Whether it's animated or not.</param>
        public override void ViewWillAppear(bool animated)
        {
            base.ViewWillAppear(animated);
            UpdateAllTabBarItems();
        }

        /// <summary>
        /// Updates the tab bar item for each page included in the TabbedPage.
        /// </summary>
        private void UpdateAllTabBarItems()
        {
            foreach(var controller in ViewControllers)
            {
                controller.TabBarItem.SetTitleTextAttributes(StandardAttributes, UIControlState.Normal);
            }
        }

        /// <summary>
        /// Stores the UITextAttributes for this class.
        /// </summary>
        /// <value>The standard attributes.</value>
        private static UITextAttributes StandardAttributes { get; } = new UITextAttributes { Font = FontManager.GetFont(9.0f)};
    }
}

FontManager.cs

using System;
using UIKit;
using {AppName}.View;

namespace {AppName}.iOS.Views
{
    /// <summary>
    /// The FontManager type is responsible for setting font changes where Xamarin.Forms elements do not have accessible font family properties.
    /// </summary>
    public static class FontManager
    {
        /// <summary>
        /// This method should be executed during program launch to configure the rendering.
        /// </summary>
        public static void ConfigureFonts()
        {
            var titleAttribute = new UITextAttributes { Font = GetFont(UIFont.LabelFontSize) };
            // Updates the ToolbarItem appearance.
            UIBarButtonItem.Appearance.SetTitleTextAttributes(titleAttribute, UIControlState.Normal);
            // Sets the NavigationBar title items. Also sets the format for TabbedPage tab items for some reason.
            UINavigationBar.Appearance.SetTitleTextAttributes(titleAttribute);
            // Just being thorough...
            UILabel.Appearance.Font = GetFont(UIFont.LabelFontSize);
        }

        /// <summary>
        /// Gets a <see cref="UIFont"/> object for the standard font with the desired size.
        /// </summary>
        /// <returns>UIFont object for use.</returns>
        /// <param name="fontSize">Font size.</param>
        public static UIFont GetFont(nfloat fontSize)
        {
            return UIFont.FromName(StandardFontName, fontSize);
        }

        /// <summary>
        /// Gets the iOS font name for the standard font for this application.
        /// </summary>
        /// <value>The name of the standard font.</value>
        public static string StandardFontName => "AvenirNextCondensed-Regular";
    }
}

Hello richseviora,

I have applied it but the font family and font size not change