Xamarin.Forms iOS Numeric Keyboard With 'Done' Button

ExtendedEntry.cs

using Xamarin.Forms;

namespace YourNamespace.Controls
{
	public class ExtendedEntry : Entry { }
}

ExtendedEntryRenderer.cs

/*
Based on example from: https://forums.xamarin.com/discussion/18346/add-done-button-to-keyboard-on-ios
*/

using System.Drawing;
using YourNamespace.Controls;
using YourNamespace.iOS.Renderers;
using UIKit;
using Xamarin.Forms;
using Xamarin.Forms.Platform.iOS;

[assembly: ExportRenderer(typeof(ExtendedEntry), typeof(ExtendedEntryRenderer))]
namespace YourNamespace.iOS.Renderers
{
	public class ExtendedEntryRenderer : EntryRenderer
	{
		protected override void OnElementChanged(ElementChangedEventArgs<Entry> e)
		{
			base.OnElementChanged(e);

			if (Element == null)
				return;

			// Check only for Numeric keyboard
			if (this.Element.Keyboard == Keyboard.Numeric)
				this.AddDoneButton();
		}

		/// <summary>
		/// <para>Add toolbar with Done button</para>
		/// </summary>
		protected void AddDoneButton()
		{
			var toolbar = new UIToolbar(new RectangleF(0.0f, 0.0f, 50.0f, 44.0f));

			var doneButton = new UIBarButtonItem(UIBarButtonSystemItem.Done, delegate
			{
				this.Control.ResignFirstResponder();
				var baseEntry = this.Element.GetType();
				((IEntryController)Element).SendCompleted();
			});

			toolbar.Items = new UIBarButtonItem[] {
				new UIBarButtonItem (UIBarButtonSystemItem.FlexibleSpace),
				doneButton
			};
			this.Control.InputAccessoryView = toolbar;
		}
	}
}

This no longer works as this.Control.InputAccessoryView is readonly.