using System;

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

namespace YourNamespace.Droid
{
    [Activity(Label = "AppName", Icon = "@drawable/icon", Theme = "@style/MainTheme", MainLauncher = true, ConfigurationChanges =            ConfigChanges.ScreenSize | ConfigChanges.Orientation)]
    public class MainActivity : global::Xamarin.Forms.Platform.Android.FormsAppCompatActivity
    {
        protected override void OnCreate(Bundle bundle)
        {
            TabLayoutResource = Resource.Layout.Tabbar;
            ToolbarResource = Resource.Layout.Toolbar;

            base.OnCreate(bundle);
            global::Xamarin.Forms.Forms.SetFlags("FastRenderers_Experimental");
            global::Xamarin.Forms.Forms.Init(this, bundle);

            DuGu.XFLib.Droid.ControlSet.Init();
            DuGu.XFLib.Droid.Services.AndroidToolBar.Init(Resource.Id.toolbar);

            LoadApplication(new App());
        }
    }
}

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

using Foundation;
using UIKit;

namespace YourNamespace.iOS
{
    [Register("AppDelegate")]
    public partial class AppDelegate : global::Xamarin.Forms.Platform.iOS.FormsApplicationDelegate
    {
        public override bool FinishedLaunching(UIApplication app, NSDictionary options)
        {
            global::Xamarin.Forms.Forms.Init();

            DuGu.XFLib.iOS.ControlSet.Init();

            LoadApplication(new App());

            return base.FinishedLaunching(app, options);
        }
    }
}

DependencyService.Get<IScreen>().GetFullSize();