UIView subclass and UIViewAppearance

CustomView.cs

using System;
using CoreGraphics;
using Foundation;
using ObjCRuntime;
using UIKit;

namespace App1
{
    [Register("CustomView")]
    public class CustomView : UIView
    {
        public CustomView()
        {
            Initialize();
        }

        public CustomView(CGRect bounds) : base(bounds)
        {
            Initialize();
        }

        void Initialize()
        {
        }

        public new static CustomViewAppearance Appearance
        {
            get
            {
                var appearance = GetAppearance<CustomView>();
                return new CustomViewAppearance(appearance.Handle);
            }
        }

        public UIColor FuffaColor
        {
            [Export("fuffaColor")]
            get => BackgroundColor;
            [Export("setFuffaColor:")]
            set => BackgroundColor = value;
        }

        public nfloat Radius
        {
            get => IntRadius.NFloatValue;
            set => IntRadius = NSNumber.FromNFloat(value);
        }

        private NSNumber IntRadius
        {
            [Export("__radius")] 
            get => NSNumber.FromNFloat(Layer.CornerRadius);
            [Export("__setRadius:")]
            set
            {
                Layer.CornerRadius = value.NFloatValue;
                ClipsToBounds = Layer.CornerRadius > 0;
            }
        }

        public class CustomViewAppearance : UIViewAppearance
        {
            private static readonly Selector FuffaColorGetter = new Selector("fuffaColor");
            private static readonly Selector FuffaColorSetter = new Selector("setFuffaColor:");
            private static readonly Selector RadiusGetter = new Selector("__radius");
            private static readonly Selector RadiusSetter = new Selector("__setRadius:");

            protected internal CustomViewAppearance(IntPtr handle) : base(handle)
            {
            }

            public UIColor FuffaColor
            {
                get => PerformSelector(FuffaColorGetter) as UIColor;
                set => PerformSelector(FuffaColorSetter, value);
            }

            public nfloat Radius
            {
                get => ((NSNumber) PerformSelector(RadiusGetter)).NFloatValue;
                set => PerformSelector(RadiusSetter, NSNumber.FromNFloat(value));
            }
        }
    }
}