CircularProgressbarView.xaml.cs

    public partial class CircularProgressbarView: ContentView
    {
        private ProgressDrawer _ProgressDrawer;

        public static readonly BindableProperty ProgressProperty = BindableProperty.Create(
            "Progress", typeof(double), typeof(CircularProgressbarView),propertyChanged:OnProgressChanged);

        public double Progress
        {
            get { return (double) GetValue(ProgressProperty); }
            set { SetValue(ProgressProperty, value); }
        }
        private static void OnProgressChanged(BindableObject bindable, object oldvalue, object newvalue)
        {
            var context = bindable as vxaml;
            context.SkCanvasView.InvalidateSurface();
        }

        public CircularProgressbarView()
        {
            InitializeComponent(); 
            var circle = new Circle(400,(info)=> new SKPoint((float)info.Width / 2,(float)info.Height / 2));
             _ProgressDrawer = new ProgressDrawer(SkCanvasView, circle, () => (float)Progress, 5,SKColors.Black, SKColors.Red);
             
        }
}