MainActivity.cs

using System;
using Android.App;
using Android.Content.PM;
using Android.Runtime;
using Android.Views;
using Android.Widget;
using Android.OS;
using Xamarin.Forms.Platform.Android;

namespace SG.Droid {
  [Activity(Label = "SG", MainLauncher = true, 
      ConfigurationChanges = ConfigChanges.ScreenSize | ConfigChanges.Orientation)]
  public class MainActivity : AndroidActivity {
    protected override void OnCreate(Bundle bundle) {
      base.OnCreate(bundle);
      Xamarin.Forms.Forms.Init(this, bundle);
      SetPage(App.GetMainPage());
    }
  }
}