CustomEntryRenderer errors

I'm trying to create a custom renderer for an entry control, and have followed this link: https://forums.xamarin.com/discussion/96991/how-to-remove-underline-in-entry

However, when I try to test the application, I get the following errors:

All of these errors are in the Android CustomEntryRenderer.cs file. What do I need to do to resolve them?

My Android CER.cs file

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

using Android.App;
using Android.Content;
using Android.OS;
using Android.Runtime;
using Android.Views;
using Android.Widget;

[assembly: ExportRenderer(typeof(CustomEntry), typeof(CustomEntryRenderer))]
namespace XPlatform.Droid
{
    public class CustomEntryRenderer : EntryRenderer
    {
        protected override void OnElementChanged(ElementChangedEventArgs<Entry> e)
        {
            base.OnElementChanged(e);

            if (Control != null)
            {
                GradientDrawable gd = new GradientDrawable();
                gd.SetColor(global::Android.Graphics.Color.Transparent);
                this.Control.SetBackgroundDrawable(gd);
                this.Control.SetRawInputType(InputTypes.TextFlagNoSuggestions);
                Control.SetHintTextColor(ColorStateList.ValueOf(global::Android.Graphics.Color.White));
            }
        }
    }
}