AdaptiveImage.cs

public AdaptiveImage()
{
    this.LayoutRoot = new Grid();
    this.Content = this.LayoutRoot;

    this.ProgressIndicator = new ProgressRing
    {
        Foreground = new SolidColorBrush { Color = Colors.White },
        Width = 100,
        Height = 100,
        HorizontalAlignment = HorizontalAlignment.Stretch,
        VerticalAlignment = VerticalAlignment.Stretch
    };
}

protected Grid LayoutRoot { get; }