how to acheive Rounded Button in Xamarin.forms?

I have a requirement of round button, to show notification badge in my app.

I am currently doing it in a custom renderer, but unable to acheive. any help would be appreciated.

button.SizeChanged += (s, args) =>
                {
                    var radius = (float)Math.Min(button.Width, button.Height);

                    // Create a drawable for the button's normal state
                    _normal = new Android.Graphics.Drawables.GradientDrawable();

                    if ((button.BackgroundColor.R.Equals(-1.0)) && (button.BackgroundColor.G.Equals(-1.0)) && (button.BackgroundColor.B.Equals(-1.0)))
                        _normal.SetColor(Android.Graphics.Color.ParseColor("#3A444D"));
                    else
                        _normal.SetColor(button.BackgroundColor.ToAndroid());

                    _normal.SetCornerRadius(radius);

                    // Create a drawable for the button's pressed state
                    _pressed = new GradientDrawable();
                    var highlight = Context.ObtainStyledAttributes(new int[] { Android.Resource.Attribute.ColorActivatedHighlight }).GetColor(0, Android.Graphics.Color.Gray);
                    _pressed.SetColor(highlight);
                    _pressed.SetCornerRadius(radius);

                    // Add the drawables to a state list and assign the state list to the button
                    var sld = new StateListDrawable();
                    sld.AddState(new int[] { Android.Resource.Attribute.StatePressed }, _pressed);
                    sld.AddState(new int[] { }, _normal);
                    Control.SetBackgroundDrawable(sld);
                };