WinFrom验证码的实现

  /// <summary>
        /// WinFrom验证码的实现
        /// </summary>
        /// <param name="pictureBox1"></param>
        /// <returns></returns>
        public static string  pictureBoxVerification(PictureBox pictureBox1) {


            Random r = new Random();
            string str = null;
            for (int i = 0; i < 5; i++)
            {
                int rNumber = r.Next(0, 10);
                str += rNumber;
            }
            //MessageBox.Show(str);
            //创建GDI对象
            Bitmap bmp = new Bitmap(150, 40);
            Graphics g = Graphics.FromImage(bmp);


            for (int i = 0; i < 5; i++)
            {
                Point p = new Point(i * 20, 0);
                string[] fonts = { "微软雅黑", "宋体", "隶属", "仿宋", "黑体" };
                Color[] colors = { Color.Yellow, Color.Red, Color.Blue, Color.Black, Color.Green };
                g.DrawString(str[i].ToString(), new Font(fonts[r.Next(0, 5)], 20, FontStyle.Bold), new SolidBrush(colors[r.Next(0, 5)]), p);
            }

            for (int i = 0; i < 20; i++)
            {
                Point p1 = new Point(r.Next(0, bmp.Width), r.Next(0, bmp.Height));
                Point p2 = new Point(r.Next(0, bmp.Width), r.Next(0, bmp.Height));
                g.DrawLine(new Pen(Brushes.Green), p1, p2);
            }

            for (int i = 0; i < 500; i++)
            {
                Point p = new Point(r.Next(0, bmp.Width), r.Next(0, bmp.Height));
                bmp.SetPixel(p.X, p.Y, Color.Black);
            }

            //将图片向前到PictureBox中
            pictureBox1.Image = bmp;

            return str;
        }