public class ValidationCode    {        Random r = new Random(DateTime.Now.Millisecond);        /// <summary>        /// 用于在生成验证码        /// </summary>        /// <param name="text">生成验证码的字符串</param>        /// <param name="img">silverlight中的Imge控件</param>        public void CreatImage(string text, Image img)         {            int height =Convert.ToInt32(img.Height);            int width = Convert.ToInt32(img.Width);            Grid Gx = new Grid();            //用于生成干扰线            Canvas cv1 = new Canvas();            for (int i = 0; i < 6; i++)            {                Polyline p = new Polyline();                for (int ix = 0; ix < r.Next(3, 6); ix++)                {                    p.Points.Add(new Point(r.NextDouble() * width,                        r.NextDouble() * height));                }                byte[] Buffer = new byte[3];                r.NextBytes(Buffer);                SolidColorBrush SC = new SolidColorBrush(Color.FromArgb(255,                    Buffer[0], Buffer[1], Buffer[2]));                p.Stroke = SC;                p.StrokeThickness = 0.5;                cv1.Children.Add(p);            }            Gx.Children.Add(cv1);            //用于生成数字            Canvas cv2 = new Canvas();            int y = 0;            int lw = 6;            double w = (width - lw) / text.Length;            int h = (int)height;            foreach (char x in text)            {                byte[] Buffer = new byte[3];                r.NextBytes(Buffer);  //用随机数填充字节数组的元素                SolidColorBrush SC = new SolidColorBrush(Color.FromArgb(255,                    Buffer[0], Buffer[1], Buffer[2]));                TextBlock t = new TextBlock();                t.TextAlignment = TextAlignment.Center;                t.FontSize = r.Next(h - 3, h); //返回一个指定范围内的数  设定字体大小<像素高度-3>                t.Foreground = SC;    //设置前景色                t.Text = x.ToString();                t.Projection = new PlaneProjection()  //对象的透视转换(类似三维效果)                {                    RotationX = r.Next(-30, 30),                    RotationY = r.Next(-30, 30),                    RotationZ = r.Next(-10, 10)                };                cv2.Children.Add(t);                Canvas.SetLeft(t, lw / 2 + y * w);                Canvas.SetTop(t, 0);                y++;            }            Gx.Children.Add(cv2);            //基于内存管理图像的类            WriteableBitmap W = new WriteableBitmap(Gx, new TransformGroup());            W.Render(Gx, new TransformGroup());            img.Source = W;        }
   }