iot/projects/Demo/Demo.iOS/Controls/CameraPreviewRenderer.cs

using Demo.iOS.Controls;
using System;
using Xamarin.Forms;
using Xamarin.Forms.Platform.iOS;

[assembly: ExportRenderer(typeof(Demo.Controls.CameraPreview), typeof(CameraPreviewRenderer))]
namespace Demo.iOS.Controls
{
    public class CameraPreviewRenderer : ViewRenderer<Demo.Controls.CameraPreview, UICameraPreview>
    {
        private UICameraPreview uiCameraPreview;

        protected override void OnElementChanged(ElementChangedEventArgs<Demo.Controls.CameraPreview> e)
        {
            base.OnElementChanged(e);
            if (e.NewElement != null)
            {
                if (Control == null)
                {
                    uiCameraPreview = new UICameraPreview(e.NewElement.Camera);
                    SetNativeControl(uiCameraPreview);
                }
            }
        }

        protected override void Dispose(bool disposing)
        {
            if (disposing)
            {
                Control.CaptureSession.Dispose();
                Control.Dispose();
            }
            base.Dispose(disposing);
        }
    }
}