Xamarin Form: Renderer override the ViewElementRenderer of Image, Image doesn't show up

I am creating android platform over a xamarin form Image control. I can have onDraw to draw something on it. I don't see the image showing on the view

    [assembly: ExportRenderer(typeof(CanvasView), typeof(CanvasViewRenderer))]
namespace Meeting.Droid
{

public class CanvasViewRenderer : VisualElementRenderer<CanvasView> 
{ 
    protected override void OnElementChanged(ElementChangedEventArgs<CanvasView> e)
    {
        base.OnElementChanged(e);

        if (e.OldElement != null || Element == null)
            return;

        page = new Page();
        var directory = Android.OS.Environment.GetExternalStoragePublicDirectory(Android.OS.Environment.DirectoryDownloads);
        var imagePath = directory + "/A.png";
        Element.Source = ImageSource.FromFile("file://" + imagePath);

        Touch += CanvasTouchEvent;
        SetWillNotDraw(false);

    }

PCL Class is :

public class CanvasView : Image
{
    public CanvasView()
    {

    }
}

Am I doing something not right.