Xamarin.Forms : Device Orientation Service

DeviceOrientation.cs

using System;

namespace MyNamespace
{
    
    public enum DeviceOrientation
    {
       Landscape,
        Portrait
    }
    
}

DeviceOrientationService.Android.cs

using System;
using Xamarin.Forms;
using MyNamespace.Android;
using Android.OS;
using Android.Views;
using Android.Content;
using Android.Runtime;
using Android.App;


[assembly: Dependency(typeof (DeviceOrientationService))]
namespace MyNamespace.Android
{
    public class DeviceOrientationService:IDeviceOrientationService
    {
        #region IDeviceOrientationService implementation

        public DeviceOrientation GetOrientation()
        {

            IWindowManager windowManager = Application.Context .GetSystemService(Context.WindowService).JavaCast<IWindowManager>();

            var rotation = windowManager.DefaultDisplay.Rotation;


            bool isLandscape = rotation == SurfaceOrientation.Rotation90 || rotation == SurfaceOrientation.Rotation270;

            return isLandscape ? DeviceOrientation.Landscape : DeviceOrientation.Portrait;

        }

        #endregion
    }
}

DeviceOrientationService.iOS.cs

using System;
using MonoTouch.UIKit;
using Xamarin.Forms;
using MyNamespace.iOS;

[assembly: Dependency(typeof (DeviceOrientationService))]
namespace MyNamespace.iOS
{
    public class DeviceOrientationService:IDeviceOrientationService
    {
        #region IDeviceOrientationService implementation

        public DeviceOrientation GetOrientation()
        {
            var currentOrientation = UIApplication.SharedApplication.StatusBarOrientation;
            bool isPortrait = currentOrientation == UIInterfaceOrientation.Portrait || currentOrientation == UIInterfaceOrientation.PortraitUpsideDown;

            return !isPortrait ? DeviceOrientation.Landscape : DeviceOrientation.Portrait;
           
        }

        #endregion


    }
}

IDeviceOrientationService.cs

using System;

namespace MyNamespace
{
    public interface IDeviceOrientationService
    {
        DeviceOrientation GetOrientation();
    }
}

Sample.cs

using System;
using System.Collections.Generic;
using System.Linq;
using Xamarin.Forms;
using System.Globalization;
using System.Collections.ObjectModel;
using System.Threading.Tasks;
using System.Threading;

namespace MyNamespace
{
    public class EnergyChartPage : ContentPage
    {
        private ChartParamsViewModel _paramsModel;
        private EnergyProductionData _model;

        private ChartServices _chartSvc;
        private IDeviceOrientationService _deviceOrientationSvc;

        public EnergyChartPage(ChartParamsViewModel parmsModel)
        {
            _deviceOrientationSvc = DependencyService.Get<IDeviceOrientationService>();
            _chartSvc = new ChartServices();
            _paramsModel = parmsModel;	
 
            var root = new StackLayout(){ Orientation = StackOrientation.Horizontal };
            Content = root;
        }

        protected override void OnAppearing()
        {
            base.OnAppearing();
            var initialOrientation = _deviceOrientationSvc.GetOrientation();
            ApplyOrientation(initialOrientation);
        }
        
        private void ApplyOrientation(DeviceOrientation orientation)
        {
            switch (orientation)
            {
                case DeviceOrientation.Portrait:
                    //TODO
                    break;
                case DeviceOrientation.Landscape:
                    //TODO
                    break;
                default:
                    break;
            }
        }
}