public class SafePicture : System.Windows.Controls.ContentControl
    {
        private ImageSource imageSource;

        public SafePicture()
        {
            Loaded += OnLoaded;
            Unloaded += SafePictureUnloaded;
        }

        private void OnLoaded(object _sender, RoutedEventArgs _routedEventArgs)
        {
            var image = Content as System.Windows.Controls.Image;
            if (imageSource != null && image != null)
                    image.Source = imageSource;
        }

        private void SafePictureUnloaded(object sender, System.Windows.RoutedEventArgs e)
        {
            var image = Content as System.Windows.Controls.Image;

            if (image != null)
            {
                imageSource = image.Source;
                image.Source = null;
            }
        }
    }