protected override void OnRender(System.Windows.Media.DrawingContext drawingContext)
        {
            FormattedText text = new FormattedText(OverlayedText, Thread.CurrentThread.CurrentUICulture,
                FlowDirection.LeftToRight, Typeface, FontSize, ForeGround);
            Point textPoint = startPoint;
            if (DesiredSize.Height > 0 && DesiredSize.Width > 0 && text.Width > 0)
            {
                textPoint.X = DesiredSize.Width / 2 - text.Width/2;
                textPoint.Y = DesiredSize.Height / 2;
            }
            drawingContext.DrawText(text, textPoint);
            drawingContext.DrawRectangle(Color, Border, new Rect(startPoint, DesiredSize));

            Uri oUri = new Uri("pack://application:,,,/DisplayTimeManager.WPF;component/Resources/Icons/loadgif.gif", UriKind.RelativeOrAbsolute);
            ImageSource lockImage = new BitmapImage(oUri);
            int imgSize = 64;
            Rect targetRect = new Rect(textPoint.X+ imgSize/2, textPoint.Y+ imgSize/2, imgSize ,imgSize);

            //animacion
            DoubleAnimation doubleAnimation = new DoubleAnimation();
            doubleAnimation.From = 0;
            doubleAnimation.To = 360;
            doubleAnimation.Duration = new Duration(TimeSpan.FromSeconds(1));
            doubleAnimation.RepeatBehavior = RepeatBehavior.Forever;
            AnimationClock myClockAngle = doubleAnimation.CreateClock();
            //y dibujamos

            var drawingGroup = new DrawingGroup();
            //drawingGroup.Transform.
            drawingGroup.Transform = new RotateTransform();
            drawingGroup.Transform.BeginAnimation(RotateTransform.AngleProperty, doubleAnimation);
            ImageDrawing imagedrawing = new ImageDrawing(lockImage, new Rect(imgSize / 2 * (-1), imgSize / 2 * (-1), imgSize, imgSize));
            //ImageDrawing imagedrawing = new ImageDrawing(lockImage,targetRect );
            drawingGroup.Children.Add(imagedrawing);
            drawingContext.DrawDrawing(drawingGroup);

            base.OnRender(drawingContext);
        }