I have been trying to set font size on Xamarin forms TabbedPage for the titles of pages on navigation bar for iOS.

I have tried to use TabbedView instead, however since I have quite few tabs.. and quite lot of data the application was slowing down and freezing. Plus I had to use content view instead of content pages.

I have tried custom renderer, I have seen no mistake in the output, I tried to debug the code it went through however no changes were applied and title remained exactly the same.

using tab;
using UIKit;
using Xamarin.Forms;
using Xamarin.Forms.Platform.iOS;

[assembly: ExportRenderer(typeof(ExtendedTabbedPage), typeof(ExtendedTabbedPageRenderer))]
namespace tab
{

    public class ExtendedTabbedPageRenderer : TabbedRenderer
    {
        protected override void OnElementChanged(VisualElementChangedEventArgs e)
        {
            base.OnElementChanged(e);

            if (TabBar != null)
            {
                ApplyTabTitleStyle();
            }
        }

        private void ApplyTabTitleStyle()
        {
            
            foreach (var item in TabBar.Items)
            {
                item.SetTitleTextAttributes(new UITextAttributes
                {
                    Font = UIFont.SystemFontOfSize(20) 
                }, UIControlState.Normal);
            }
        }
    }
}

using System;
using Xamarin.Forms;

namespace tab
{
    public class ExtendedTabbedPage : TabbedPage
    {
        public ExtendedTabbedPage()
        {
        }
    }
}

I also tried this approach https://xamgirl.com/extending-tabbedpage-in-xamarin-forms/