学习笔记：利用GDI+生成简单的验证码图片

学习笔记：利用GDI+生成简单的验证码图片

 1 /// <summary>

 2         /// 单击图片时切换图片

 3         /// </summary>

 4         /// <param name="sender"></param>

 5         /// <param name="e"></param>

 6         private void pictureBox1_Click(object sender, EventArgs e)

 7         {

 8             Random r = new Random();

 9             string str = string.Empty;

10             //生成5位随机数如 90531

11             for (int i = 0; i < 5; i++)

12             {

13                 str += r.Next(0, 10);

14             }

15             Bitmap bitmap = new Bitmap(150, 40);

16             Graphics g = Graphics.FromImage(bitmap);

17             //预定义几种字体样式和颜色

18             string[] fonts = { "微软雅黑", "宋体", "黑体", "隶书", "仿宋" };

19             Color[] colors = { Color.Yellow, Color.Blue, Color.Black, Color.Red, Color.Orange };

20             //因为每一数字的字体和颜色可能不同，

21             //因此循环将生成的随机数每一数字绘制到图片

22             for (int i = 0; i < str.Length; i++)

23             {

24                 Point p = new Point(i * 30, 0);

25                 g.DrawString(str[i].ToString(), new Font(fonts[r.Next(0, 5)], 20, FontStyle.Bold), new SolidBrush(colors[r.Next(0, 5)]), p);

26             }

27             //循环在图片范围内绘制出50条线

28             for (int i = 0; i < 50; i++)

29             {

30                 //保证线的起始点都在图片范围内

31                 Point p1 = new Point(r.Next(0, bitmap.Width), r.Next(0, bitmap.Height));

32                 Point p2 = new Point(r.Next(0, bitmap.Width), r.Next(0, bitmap.Height));

33                 g.DrawLine(new Pen(Brushes.Green), p1, p2);

34             }

35             //添加一些像素点

36             for (int i = 0; i < 300; i++)

37             {

38                 Point p1 = new Point(r.Next(0, bitmap.Width), r.Next(0, bitmap.Height));

39                 bitmap.SetPixel(p1.X, p1.Y, Color.Green);

40             }

41             //在winForm中用PictureBox中显示出来

42             pictureBox1.Image = bitmap;

43         }

View Code

 最终效果如下