StackView for Xamarin.iOS without the need for AutoLayout constraints

StackView.cs

using System;
using System.Linq;
using CoreGraphics;
using UIKit;

namespace iOS
{
    public class StackView : UIView
    {
        nfloat _previousWidth;
        nfloat _previousHeight;

        public event EventHandler SizeChanged;

        bool _autoAdaptSize;
        public bool AutoAdaptSize
        {
            get
            {
                return _autoAdaptSize;
            }
            set
            {
                _autoAdaptSize = value;
                SetNeedsLayout();
            }
        }

        StackOrientation _orientation;
        public StackOrientation Orientation
        {
            get
            {
                return _orientation;
            }
            set
            {
                _orientation = value;
                SetNeedsLayout();
            }
        }

        public override void LayoutSubviews()
        {
            base.LayoutSubviews();

            PositionSubviews();

            if (_previousWidth != Bounds.Width || _previousHeight != Bounds.Height)
            {
                _previousWidth = Bounds.Width;
                _previousHeight = Bounds.Height;

                SizeChanged?.Invoke(this, EventArgs.Empty);
            }
        }

        void PositionSubviews()
        {
            if (Subviews?.Any() == true)
            {
                var pos = 0.0;

                foreach (var v in Subviews)
                {
                    if (Orientation == StackOrientation.Horizontal)
                    {
                        v.Frame = new CGRect(pos, v.Frame.Y, v.Frame.Width, v.Frame.Height);
                        pos += v.Frame.Width;
                    }
                    else
                    {
                        v.Frame = new CGRect(v.Frame.X, pos, v.Frame.Width, v.Frame.Height);
                        pos += v.Frame.Height;
                    }
                }

                if (AutoAdaptSize)
                {
                    if (Orientation == StackOrientation.Horizontal)
                    {
                        Frame = new CGRect(Frame.X, Frame.Y, pos, Frame.Height);
                    }
                    else
                    {
                        Frame = new CGRect(Frame.X, Frame.Y, Frame.Width, pos);
                    }
                }
            }
            else if (AutoAdaptSize)
            {
                Frame = new CGRect(Frame.X, Frame.Y, 0, 0);
            }
        }

        public override void AddSubview(UIView view)
        {
            base.AddSubview(view);
            SetNeedsLayout();
        }

        public enum StackOrientation
        {
            Horizontal, Vertical
        }
    }
}