.Net学习笔记----2015-07-10(使用GDI绘制验证码)

        /// <summary>
        /// 点击更换验证码
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void pictureBox1_Click(object sender, EventArgs e)
        {
            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(120, 40);
            Graphics g = Graphics.FromImage(bmp);
            
            //将产生的随机数字符串放到图片上
            for (int i = 0; i < 5; i++)
            {
                Point p = new Point(i * 20, 0);
                string[] fonts = {"微软雅黑","宋体","黑体","隶书","仿宋"};
                Color[] colors = {Color.Yellow,Color.AliceBlue,Color.Black,Color.Blue,Color.Green,Color.Red };
                g.DrawString(str[i].ToString(),
                    new Font(fonts[r.Next(0, 5)], 20, FontStyle.Bold),
                    new SolidBrush(colors[r.Next(0, 5)]), p);
            }
            //在数字图片上画直线
            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);
            }
            //在图片上添加像素点
            for (int i = 0; i < 800; i++)
            {
                Point p = new Point(r.Next(0, bmp.Width), r.Next(0, bmp.Height));
                bmp.SetPixel(p.X, p.Y,Color.DarkBlue);
            }


            //将图片放到PictureBox中
            pictureBox1.Image = bmp;
        }