HeaderViewCell Renderer

HeaderViewCell.cs

using Xamarin.Forms;

namespace A11YGuide.Controls
{
    public class HeaderViewCell : ViewCell
    {

    }
}

HeaderViewCellRenderer.cs

using A11YGuide.Controls;
using A11YGuide.Controls.Lists;
using A11YGuide.iOS.Controls;
using A11YGuide.iOS.Controls.Lists;
using UIKit;
using Xamarin.Forms;
using Xamarin.Forms.Platform.iOS;

[assembly: ExportRenderer(typeof(HeaderViewCell), typeof(HeaderViewCellRenderer))]
namespace A11YGuide.iOS.Controls
{
    public class HeaderViewCellRenderer : ViewCellRenderer
    {
        static readonly BindableProperty RealCellProperty = BindableProperty.CreateAttached("RealCell", typeof(UITableViewCell), typeof(Cell), null);

        public override UITableViewCell GetCell(Cell item, UITableViewCell reusableCell, UITableView tv)
        {
            var viewCell = (ViewCell)item;

            if (!(reusableCell is NativeHeaderViewCell cell))
            {
                cell = new NativeHeaderViewCell(item.GetType().FullName);
            }

            cell.ViewCell = viewCell;
            SetRealCell(item, cell);

            return cell;

        }

        private static void SetRealCell(BindableObject cell, UITableViewCell renderer)
        {
            cell.SetValue(RealCellProperty, renderer);
        }
    }
}

NativeHeaderViewCell.cs

using System;
using BigTed;
using UIKit;
using Xamarin.Forms;
using Xamarin.Forms.Platform.iOS;

namespace A11YGuide.iOS.Controls.Lists
{
    public class NativeHeaderViewCell : UITableViewCell, INativeElementView
    {
        WeakReference<IVisualElementRenderer> _rendererRef;
        private ViewCell _viewCell;

        public NativeHeaderViewCell(string key) : base(UITableViewCellStyle.Default, key)
        {
        }

        Element INativeElementView.Element => ViewCell;

        public ViewCell ViewCell
        {
            get => _viewCell;
            set
            {
                if (_viewCell == value)
                    return;
                UpdateCell(value);
            }
        }

        private void UpdateCell(ViewCell cell)
        {
            ICellController cellController = ViewCell;
            if (cellController != null)
                Device.BeginInvokeOnMainThread(cellController.SendDisappearing);

            _viewCell = cell;
            cellController = cell;

            Device.BeginInvokeOnMainThread(cellController.SendAppearing);
            var renderer = GetNewRenderer();

            Platform.SetRenderer(ViewCell.View, renderer);
        }

        public override void LayoutSubviews()
        {
            //This sets the content views frame.
            base.LayoutSubviews();

            var contentFrame = ContentView.Frame;
            var view = ViewCell.View;

            Layout.LayoutChildIntoBoundingRegion(view, contentFrame.ToRectangle());

            if (_rendererRef == null)
                return;

            if (_rendererRef.TryGetTarget(out var renderer))
            {
                renderer.NativeView.Frame = view.Bounds.ToRectangleF();
            }
        }

        IVisualElementRenderer GetNewRenderer()
        {
            var newRenderer = Platform.CreateRenderer(ViewCell.View);
            _rendererRef = new WeakReference<IVisualElementRenderer>(newRenderer);
            ContentView.AddSubview(newRenderer.NativeView);
            return newRenderer;
        }
    }
}

View.xaml

<ListView Grid.Row="0"
          BackgroundColor="#162B2B"
          SeparatorVisibility="None"
          HasUnevenRows="True"
          IsGroupingEnabled="True"
          Header="{Binding}"
          Footer="{Binding}"
          VerticalOptions="StartAndExpand">

  <ListView.GroupHeaderTemplate>
    <DataTemplate>
      <controls1:HeaderViewCell Height="30">
        <Grid BackgroundColor="#162B2B" RowSpacing="0" />
      </controls1:HeaderViewCell>

    </DataTemplate>
  </ListView.GroupHeaderTemplate>
</ListView>