ExtendedEntryRenderer.cs

[assembly: ExportRenderer(typeof(ExtendedEntry), typeof(ExtendedEntryRenderer))]
namespace EntryValidationBorder.iOS
{
	public class ExtendedEntryRenderer : EntryRenderer
	{
		protected override void OnElementPropertyChanged(object sender, System.ComponentModel.PropertyChangedEventArgs e)
		{
			base.OnElementPropertyChanged(sender, e);

			if (Control == null || this.Element == null) return;

            if (e.PropertyName == ExtendedEntry.IsBorderErrorVisibleProperty.PropertyName){
				if (((ExtendedEntry)this.Element).IsBorderErrorVisible)
				{
					this.Control.Layer.BorderColor = ((ExtendedEntry)this.Element).BorderErrorColor.ToCGColor();
					this.Control.Layer.BorderWidth = new nfloat(0.8);
					this.Control.Layer.CornerRadius = 5;
				}
				else
				{
					this.Control.Layer.BorderColor = UIColor.LightGray.CGColor;
					this.Control.Layer.CornerRadius = 5;
					this.Control.Layer.BorderWidth = new nfloat(0.8);
				}

            }
		}

	}
}