Linking with Custom Renderers

CurvedSearchBar.cs

using Xamarin.Forms;

namespace MyApp.Views.Controls {
    public class CurvedSearchBar : SearchBar {
        public static readonly BindableProperty CornerRadiusProperty =
            BindableProperty.Create("CornerRadius", typeof(float), typeof(CurvedSearchBar), 0.0f);

        public float CornerRadius {
            get { return (float)GetValue(CornerRadiusProperty); }
            set { SetValue(CornerRadiusProperty, value); }
        }
    }
}

CurvedSearchBarRenderer.cs

[assembly: ExportRenderer(typeof(CurvedSearchBar), typeof(CurvedSearchBarRenderer))]
namespace MyApp.iOS.Renderer {
    [Preserve(AllMembers = true)]
    public class CurvedSearchBarRenderer : SearchBarRenderer {
    
        // Required Default Constructor for Custom Renderers
        public CurvedSearchBarRenderer() { }

        protected override void OnElementChanged(ElementChangedEventArgs<SearchBar> args) {
            base.OnElementChanged(args);

            if (args.OldElement != null || args.NewElement == null)
                return;

            try {
                Control.Layer.MasksToBounds = true;
                var curvedsbar = (CurvedSearchBar)args.NewElement;
                Control.Layer.CornerRadius = curvedsbar.CornerRadius;
            } catch (Exception e) {
                Debug.WriteLine(e);
            }
        }

        protected override void OnElementPropertyChanged(object sender, System.ComponentModel.PropertyChangedEventArgs e) {
            base.OnElementPropertyChanged(sender, e);
            if (e.PropertyName == CurvedSearchBar.CornerRadiusProperty.PropertyName) {
                Control.Layer.CornerRadius = ((CurvedSearchBar)Element).CornerRadius;
            }
        }
    }
}