Rounded Box Renderer for Android

using System;
using System.ComponentModel;
using Xamarin.Forms;
using Xamarin.Forms.Platform.Android;
using Android.Graphics;
using Shared.UserManagment.Controls;

[assembly: ExportRenderer(typeof(RoundedBox), typeof(<Name Space Name>.RoundedBoxRenderer))]

namespace <Name Space Name>
{
    public class RoundedBoxRenderer : BoxRenderer
    {
        protected override void OnElementChanged(ElementChangedEventArgs<BoxView> e)
        {
            base.OnElementChanged(e);

            SetWillNotDraw(false);

            Invalidate();
        }

        protected override void OnElementPropertyChanged(object sender, PropertyChangedEventArgs e)
        {
            base.OnElementPropertyChanged(sender, e);

            if (e.PropertyName == RoundedBox.CornerRadiusProperty.PropertyName)
            {
                Invalidate();
            }
        }

        public override void Draw(Canvas canvas)
        {
           
            //Xamarin.Forms.Color.Transparent

            var box = Element as RoundedBox;
            var rect = new Rect();
            var paint = new Paint()
            {    
                Color = box.BackgroundColor.ToAndroid(),
                AntiAlias = true,
            };

            //paint.SetXfermode(new PorterDuffXfermode(PorterDuff.Mode.DstAtop));

            GetDrawingRect(rect);

            var radius = (float)(rect.Width() / box.Width * box.CornerRadius);
            paint.SetStyle(Paint.Style.Stroke);
            paint.StrokeWidth = 2;
            canvas.DrawRoundRect(new RectF(rect), radius, radius, paint);

            //paint.Color = Xamarin.Forms.Color.Black.ToAndroid();

            //canvas.DrawCircle(10,10,40, paint);
        }
    }
}