WPF使用storyboard播放图像并能鼠标拖动问题

求助：使用Storyboard创建多张图像连续从左到右播放的动画，现要求可以手动鼠标拖动某张图像，并能左右移动，该如何实现呢？
下面ss是一个wrappanel控件。目前已经实现了自动播放。
double totalWidth = 0;
            double tt = ss.ActualWidth;
            for (int i = 2; i < 8; i++)
            {
                BitmapImage biReserveImage = new BitmapImage();
                biReserveImage.BeginInit();
                biReserveImage.UriSource = new Uri(@"D:\scenery" + String.Format("{0:D1}", i) + ".jpg", UriKind.RelativeOrAbsolute);
                biReserveImage.EndInit();
                totalWidth += biReserveImage.Width;

                Image ii = new Image();
                ii.Source = biReserveImage;
               
                ss.Children.Add(ii);
            }
            myStoryboard = new Storyboard();
            ss.RenderTransform = new TranslateTransform();
            DependencyProperty[] propertyChain = new DependencyProperty[]
            {
               Image.RenderTransformProperty,
               TranslateTransform.XProperty
            };
            DoubleAnimation InDoubleAnimation = new DoubleAnimation();
            InDoubleAnimation.From = 0;
            InDoubleAnimation.To = -totalWidth + gg.ActualWidth;
            InDoubleAnimation.Duration = new Duration(TimeSpan.FromSeconds(20));

            InDoubleAnimation.AccelerationRatio = 0.1;
            InDoubleAnimation.DecelerationRatio = 0.5;
            InDoubleAnimation.FillBehavior = FillBehavior.HoldEnd;

            Storyboard.SetTargetName(InDoubleAnimation, "ss");

            Storyboard.SetTargetProperty(InDoubleAnimation, new PropertyPath("(0).(1)", propertyChain));
            myStoryboard.Children.Add(InDoubleAnimation);
            //myStoryboard.Duration = new Duration(TimeSpan.FromSeconds(10));
            myStoryboard.RepeatBehavior = RepeatBehavior.Forever;

            myStoryboard.Begin(ss, true);